Talk:Climate change/Archive 95

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Food and health

This is the comparison between the section as it is now (and as it was a little earlier)

The WHO calls climate change the greatest threat to global health in the 21st century. Extreme weather leads to injury and loss of life, and crop failures to malnutrition. Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria. Young children are the most vulnerable to food shortages. Both children and older people are vulnerable to extreme heat. The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition. Reductions in food availability and quality alone could lead up to 530,000 deaths between 2010 and 2050. By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity.

Climate change is affecting food security. It has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010. Future warming could further reduce global yields of major crops. Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative. Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts. Climate change also impacts fish populations. Globally, less will be available to be fished. Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change

and the version I rewrote, and which was just reverted.

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. They estimated that between 2030 and 2050, climate change could cause around 250,000 additional deaths per year. They assessed factors such as coastal flooding, deaths from heat exposure in elderly people, increased transmission of pathogens behind infectious diseases such as malaria, diarrhea and dengue fever and childhood malnutrition. In the early 21st century, less than a third of the global population lives in areas where combinations of extreme heat and humidity that can kill people (particularly children and the elderly) occasionally occur, such as during the 2003 European heatwave. By 2100, these areas will expand to cover 50% to 75% of the population.

Climate change is affecting food security. Global fishery yields will decline as every degree of warming reduces total fish biomass. By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. Global yields of staple crops have also been negatively affected by climate change, and the impacts will become worse as the warming increases, in spite of the CO2 fertilization effect. The risk of years with crop failures in multiple areas would also increase significantly even under low emissions. By 2050, between 8 and 80 million extra people would be at risk of hunger due to climate change, compared to its absence. However, total crop yields to date have been increasing due to improved farming practices and agricultural expansion. Under low and intermediate emissions, these developments are expected to continue to improve food security in most hunger-prone regions like Sub-Saharan Africa and South Asia. Food security is unlikely to improve under high emissions. Between 2010 and 2050, around 530,000 deaths could be caused by increases in malnutrition under high emissions. This mortality would be around 70% lower under low emissions.

Climate change would not affect agricultural land equally. Small islands and regions that are already dry or dependent on glacier water have a higher risk of agricultural water stress due to climate change. Impacts on crop production may be positive at northern latitudes, but are likely to be negative in low-latitude countries. Some places may stop being able to support agriculture and livestock rearing outright: by 2100, areas which currently account for 5% agricultural production are likely to stop being suitable under low emissions, while under high emissions, they would account for 31%. For livestock, 8% and 34% would become unsuitable. Those projections do not account for potential shifts of agriculture to other areas. Worldwide decreases in land suitable for agriculture would be less pronounced, but they are still expected, particularly after 2100.

A quick summary of the differences.

• Removed the four sentences between "the greatest threat to global health" and "250,000 additional deaths per year" because by and large, they said the same thing as the "they assessed" sentence.

• Added the present-day baseline for "climate conditions that are life-threatening" because that statistic can be read very differently in the absence of that information. Following that, I felt I had to expand on the idea further. Perhaps some of that explanation can be cut, but I do not see how we can avoid using the baseline.

• My sentence on fisheries actually has the same wordcount as the two sentences in the current article, and I believe it is a more accurate and encyclopaedic phrasing.

• Added a mention of AR6 livestock projections, since not mentioning impacts on livestock at all is untenable.

• Phrasing on reduced crop yields is fairly similar and about the same size. The greatest difference is the mention of CO₂ fertilization effect and that it doesn't overcome negative effects, which I consider to be an important point.

• Mentioned the increase of compound (multi-breadbasket) crop failures, which is clearly important.

• "Up to 183 million" figure, cited to the 2019 IPCC special report, was undated, and I decided AR6 year 2050 figure was superior.

• Increase in total global yields to date is a fact. Anyone who doubts can check Our World in Data, or refer to the studies which mention that yield declines have been statistically extracted from the increasing trend. It's also practically necessary context for the next part.

• The same World Bank report which is cited in the article for the "130 million in poverty by 2030" figure also has a graphic on page 4 which appears to unequivocally state exactly what I wrote in that section.

• Springmann study was awfully mis-cited earlier: until recently, this Featured Article claimed it estimated annual mortality of 530,000 rather than over 40 years, which does not appear supported by its text in any way. I further clarified that "Adoption of climate-stabilisation pathways" phrase in that paper seems to make it clear the 530,000 figure was for RCP 8.5 or thereabouts.

• The additional sentences about agricultural land potentially becoming unsuitable are admittedly awkwardly phrased now that I look at it. I also do not know how we can justify omitting those projections outright.

So, what are the other editors' opinions about this section? InformationToKnowledge (talk) 22:39, 1 February 2024 (UTC)

I made some changes:

1) Removed 530,000 figure and Up to 183 million parts, changed those with AR6 (8-80 million by 2050).

2) Re-worded extremely hot and uninheritable climate parts, so the wording is less close to the wording used by the source.

I'm also ok with expanding the explanation for the heat and humidity part, using 2003 European heatwave as an example. Bogazicili (talk) 12:08, 2 February 2024 (UTC)

I appreciate your efforts. However, I do not fully agree with either change. To be fair, there is a lot of complexity with underlying research.

1) I agree with removing the AR5 "183 million" part, but not the 530,000 figure. For one thing, it is actually cited in AR6 as well (subsection "7.3.1.9.2 Climate Change, Carbon Dioxide, Diets, and Health") Secondly, it actually looks at the subject completely differently. It suggests that nearly all of those deaths would be caused not by hunger, but lack of vitamins and other micronutrients due to reduced availability of fruits and vegetables. This is very different from most model projections, which only look at the four staple crops, and this is likely the reason the IPCC found it worth citing.

Secondly, I'll have to admit to an embarrassing error. The earlier description of the study in this article, which I thought was egregiously wrong

Over 500,000 more adult deaths are projected yearly by 2050 due to reductions in food availability and quality.

Was actually more accurate than what I replaced it with. The study is paywalled and has a remarkably ambiguous abstract. It never uses words like "yearly" or "annually", and this sentence

The model projects that by 2050, climate change will lead to per-person reductions of 3·2% (SD 0·4%) in global food availability, 4·0% (0·7%) in fruit and vegetable consumption, and 0·7% (0·1%) in red meat consumption. These changes will be associated with 529 000 climate-related deaths worldwide (95% CI 314 000–736 000), representing a 28% (95% CI 26–33) reduction in the number of deaths that would be avoided because of changes in dietary and weight-related risk factors between 2010 and 2050.

Convinced me that the paper must be talking about the entire 2010-2050 period. It wasn't until I saw AR6 cite it as "an additional 529,000 deaths a year by 2050" that I realized this was wrong, and the original was more accurate.

However, focusing on the 530,000 figure might be missing the larger point - which is that this study still expects the overall number of deaths from hunger to go down, substantially. If 529,000 deaths reduces the number of lives saved by 28%, then that number is around 2 million, and the net figure is a decrease of ~1.5 million. The full text says as much:

Climate change reduced the number of avoided deaths

It also confirms that this is under RCP8.5: for RCP2.6, it is around 150,000, and for RCP4.5, some 350,000-400,000 depending on the SSP. This largely confirms the point I tried to make when citing year 2014 World Bank report in the version which was reverted.

So, I am not sure what would be the best way to cite this paper in the article, but it's clear that we cannot ignore it outright.

2) The main issue I highlighted here was that "live...in uninhabitable climates" is an obvious contradiction - if people can live in a place, it is, by definition, not uninhabitable. I looked at the source study (the one which first made this claim that was subsequently cited by our reference) again, and I confirmed that it never says "uninhabitable".

What it does say is "1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y" in the abstract, and similar phrases later in the text.

The study is often interpreted as if it suggests that all of those people would not actually live in those climates and migrate elsewere, but it does not actually explicitly say that at any point. If anything, it repeatedly suggests the opposite.

Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate.

and

As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.

and

Obviously, our hypothetical redistribution calculations cannot be interpreted in terms of expected migration.

It's probably a good idea to read the entire paper before considering how to handle it. Perhaps, we should also cite it directly, instead, or at least in addition to, the review article we are currently citing. I think one thing is clear - the current sentence in the article

With worst-case climate change, models project that almost one-third of humanity might live in Sahara-like uninhabitable and extremely hot climates - does not really address the issues raised.

My suggestions are:

• Drop both "live" and "uninhabitable". Something like "almost one-third of humanity might end up in climates as hot as the Sahara Desert" is more accurate to the paper and should leave no room for misunderstandings. After that, we can attach "and those climates are unlikely to support permanent populations" or something like that to the end of that sentence.
• Specify the timeline. It feels incredible, but the article just says this, but does not actually note by when. In the original paper, this projection is for 2070. It seems like the review dropped that part, however.
• Potentially specify the full range. The review only cites the worst case, but the original paper says "1 to 3 billion people" (i.e. RCP 2.6 to RCP 8.5) and the supporting information clarifies that it'll be around 2 billion under RCP 4.5 Yes, it will add a few words, but it should be worth it.

InformationToKnowledge (talk) 13:56, 2 February 2024 (UTC)

P.S. I am sorry to say this, but way you cited AR6 for the year 2050 figure is not accurate either.

Your phrase: Under a high emission scenario, climate change is expected to place an extra 8 to 80 million people at risk of hunger by 2050.

AR6: Climate change impacts could increase the global number of people at risk of hunger in 2050 by 8 million people under a scenario of sustainable development (SSP1) and 80 million people under a scenario of reduced international cooperation and low environmental protection (SSP3), with populations concentrated in sub-Saharan Africa, South Asia and Central America

Base SSPs are not emission scenarios - they are purely about development and geopolitics, and are only associated with emission projections later - SSP2-4.5, SSP5-8.5, etc. I.e. the IPCC's implication seems to be that those changes in development and geopolitics would affect vulnerability from hunger due to climate change a lot more than the actual extent of climate change, at least for the next few decades. The wording I used in the lead of Effects of climate change on agriculture - climate change is expected to place an extra 8 to 80 million people at risk of hunger by 2050 (depending on the intensity of future warming and the effectiveness of adaptation measures - may not be the ideal rephrasing of this, but it is certainly a lot closer to its meaning. InformationToKnowledge (talk) 14:40, 2 February 2024 (UTC)

AR6 WG2: "for example, between 8 million under SSP1-6.0 to up to 80 million people under SSP3-6.0." So those are 6 C projections. That's why I said high emissions. But I'm also ok with the wording on Effects of climate change on agriculture. Bogazicili (talk) 15:37, 2 February 2024 (UTC)

...I just remembered I never updated my download of AR6 WG2 from the Final Draft they presented in early 2022 to the current, full version they quietly uploaded a lot later. You are right, one of the edits they made was specifying "-6.0" for both SSPs in that sentence. And yes, RCP 6 is a fairly high emission scenario, so your wording might actually be better. I'll have to think about it more.

Finally, I would like to note that if by "6 C", you mean +6C warming then not quite. 6 stands for RCP 6.0, which was the least-often used of the four pre-SSP scenarios, and nowadays, if studies go beyond the "2.6/4.5/8.5" trifecta, they usually use SSP3-7.0. Still, according to , RCP 6.0 would result in about 3.2 C by 2100 (and 2C by 2050 or thereabouts, which is more immediately relevant to this agricultural projection). After 2300, it would apparently fluctuate between 5 and 6 C up until at least 2500, and probably well beyond that too. (Remember that the figure is relative to 2000-2019, so it needs to be increased by 1 degree to be compared to increases from preindustrial.) InformationToKnowledge (talk) 16:14, 2 February 2024 (UTC)

P.S. It now feels really tempting to describe the projection as An extra 8 to 80 million people would be at risk of hunger if global warming reaches 2°C by 2050, depending on the extent of socioeconomic development and adaptation. If this doesn't cross into WP:SYNTH, I probably would do just that. InformationToKnowledge (talk) 16:23, 2 February 2024 (UTC)

Speaking generally, I like your changes to the first paragraph, but I think you have way too much content here on food security. The second and third paragraphs just don't say much. At most, agricultural land management will need to change and some foods like meat and fish may become more expensive. Correct me if I'm wrong, but food security looks like a much less signficant issue than other impacts like heat waves, flooding, and fire. If it were me, I'd look to combine the second and third paragraphs and cut half the content there. Efbrazil (talk) 20:06, 2 February 2024 (UTC)

Alright, this is the revised version. Down to two paragraphs (though the second could certainly be split into two smaller ones), and it should hopefully be clear enough to address your misperception about this topic's significance.

In the early 21st century, less than a third of the global population lives in areas where combinations of extreme heat and humidity that can kill people (particularly children and the elderly) occasionally occur, such as during the 2002 India heatwave. By 2100, these areas will expand to cover 50% to 75% of the population. The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. They concluded that it would increase the transmission of pathogens behind infectious diseases such as malaria, diarrhea and dengue fever, and add to deaths from coastal flooding, heat exposure in elderly people, and childhood malnutrition. Between 2030 and 2050, these factors could cause around 250,000 additional deaths per year. Under a warming of 4 °C, agricultural labourers in Sub-Saharan Africa, Southeast Asia and South America will often experience too much heat stress to work. In the worst-affected areas, this could reach 250 days a year.

Global fishery yields will decline as every degree of warming reduces total fish biomass. By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. Crop yields are already getting negatively affected by stronger heatwaves and water stress, but globally, this has so far been strongly outweighted by greater farm productivity and agricultural expansion. This is expected to continue into the near future, and there'll most likely be fewer malnutrition-related deaths in 2050 than now. At higher warming levels, climate risks to agriculture will increase substantially after 2050. By 2100, total land area suitable for key staple crops would decline by over 10% with high emissions. Total land area includes wilderness like forests and plains. Out of areas already used for agriculture and livestock rearing, around a third may stop being suitable under high emissions.

The first paragraph is larger, because I moved the part about agricultural labour from the inequality section, since it just seems to fit better here. The total size of the paragraph is about the same as it is now, and the first paragraph in "Inequality" would obviously become a lot smaller.(I think it would be a good idea to add a bit more detail about other economic impacts to that paragraph instead, like the skyrocketing insurance costs?)

In the second, I avoided most specific numbers around 2050 since they would be less important than the countervailing progress trend anyway. On the other hand, I rephrased the agricultural land part to make it clear just what is being lost. If you look at one graphic from my reference for total crop area, Lyon et al, 2021, you'll see that what it considers suitable agricultural land (whether now or in the future) includes the entirety of the Amazon rainforest, all of the boreal forests and eventually, the thawed tundra. To make the point even clearer, I found a fascinating study from France which suggests that the country would likely end up ploughing some of its forests in the future, particularly with high emissions. So, yes, it seems like we can offset the impact of climate change in this way, but it'll be a disaster for biodiversity.

And if you think that it would be better to split the second paragraph in two (probably at the "Higher warming levels" mark), then I would strongly suggest mentioning increase in short-term crop failure events again. The earlier, even larger version, which was reverted by Femke, mentioned a paper which found that if global food exports dropped by 10%, 55 million would lose over 5% of their calorie intake, and if Russia, the US and Thailand had sufficiently bad harvests to forbid food exports, 200 million people would. Even if 5% does not sound like much, you probably aware of the connections between poor harvests in 2010, food export bans and the Arab Spring. I am not sure on the best way to phrase this point within our size limits, but it would be unfortunate if we failed to mention that climate-driven events do not have to starve (a lot of) people to death to substantially increase instability. InformationToKnowledge (talk) 13:32, 3 February 2024 (UTC)

P.S. I forgot to mention that I changed the 2003 European heatwave to a 2002 Indian heatwave, because a more careful look at the explanatory article for that paper (including an embedded infographic) suggests that it did not consider Europe vulnerable at present under its methodology! (With the commentary in the article instead seeming to bring up the 2003 heatwave as an example of the study's limitations.) Since it does consider India vulnerable, that event would be truer to the paper's text. (We really need to at least find an image for that heatwave, though, even if the text is already dramatic enough.) InformationToKnowledge (talk) 13:36, 3 February 2024 (UTC)

The malnutrition issue has lot more to do with equitable food distribution than it does with production. Right now the vast majority of our arable land is used for livestock, livestock feed, or fuel supplements. We also waste at least a third of the food we produce.

Here is a rewrite of what you did, edit summary is down below:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. Deaths will be caused by coastal flooding, childhood malnutrition, exposure to heat and humidity, and from increased transmission of infectious diseases such as malaria, diarrhea and dengue fever. Between 2030 and 2050 these factors could be causing 250,000 additional deaths per year, particularly threatening children and the elderly. Deadly heat waves such as the 2022 India–Pakistan heat wave will expand their range and could go from threatening 1/3rd of the world's population to about 2/3rds of it by 2100.

Global fishery yields will decline as every degree of warming reduces total fish biomass. By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. Crop yields are already getting negatively affected by stronger heatwaves and water stress, but globally, this has been strongly outweighted by greater farm productivity. This is expected to continue into the near future, but climate risks to agriculture will increase substantially at higher warming levels. Heat stress prevents agricultural labourers from working, and if warming reaches 4 °C then laborers in tropical zones could be unable to work 250 days per year. Out of areas currently used for agriculture and livestock rearing, a third may stop being suitable for use under high emission scenarios.

First paragraph changes:

• I combined the first two sentences of the first paragraph and moved them to later. The WHO statement is a better introductory sentence, and the first two sentences were awkward and wordy as written.
• Resequenced the sentence on health threat enumeration by WHO
• The statement about heat stress to those working should really not be limited to 4 C. I assume that the 4 C statement is meant for the 250 days a year metric, so I combined those sentences.
• The structure of the paragraph now goes from minimal impact (2030 to 2050) to more (2100 average) to extreme (4 C) and has fewer words.
• I switched the 2002 India heatwave to the more current 2022 India–Pakistan heat wave.

The second paragraph:

• My understanding is that agricultural land use has actually been declining lately, as efficiencies in farming increase yields per acre. If you have a source proving me wrong then great, but for now I just deleted "agricultural expansion".
• There was some grammatical issues I fixed
• This issue will be one of distribution, not production, so I cut it: "fewer malnutrition-related deaths in 2050 than now"
• Total land area available for agriculture is much less interesting than loss of existing agricultural land, so I cut total land area so the focus could be on existing agricultural land.
• As food and land has less content overall, I moved the sentence on agricultural labor back into it.

Efbrazil (talk) 18:09, 3 February 2024 (UTC)

Added to the article. The only real change I made was to the last sentence; from a third may stop being suitable for use to a third may stop being usable by 2100, both specifying the date and making the wording less awkward.

Strictly speaking, I believe that the apparent peaking of agricultural land had been very recent, while the references about impacts of climate change on historical yields started detecting it from 1981. Back then, net expansion had still been ongoing. However, this point is too minor to quibble over in such a high-level article. InformationToKnowledge (talk) 19:13, 3 February 2024 (UTC)

With this done, any suggestions regarding the other discussion here, about the "human niche" study and Sahara-like climates? I actually found a reference which appears to question at least some of its premises, but it has attracted much less attention than the original study (so far), so I am unsure on how to handle it, at least for this article. InformationToKnowledge (talk) 19:13, 3 February 2024 (UTC)

Great! Glad we came together on this so quickly.

Regarding this sentence: With worst-case climate change, models project that almost one-third of humanity might live in Sahara-like uninhabitable and extremely hot climates

Like you say, the alamist studies and language attract the media attention, not the corrections or qualifications to those studies. Ideally, look for an IPCC source talking about desertification in the likely 2 C to 3 C range and use that as basis to present the issue. The general issue is simply that deserts are likely to expand in many areas and displace arable land. Efbrazil (talk) 22:03, 3 February 2024 (UTC)

I re-added 8 to 80 million part. We can also add something like "depending on the effectiveness of adaptation measures" (given the range is for SSP1-6.0 to SSP3-6.0), but this might be redundant. I also returned the previous wording for "life-threatening due to combined effects of extreme heat and humidity" part. The example chosen seemed random. "combined effects of extreme heat and humidity" seems more descriptive than just saying deadly heatwaves with a random example. Also about 2/3rds is problematic (did you just average out 50% to 75%?) Bogazicili (talk) 16:26, 4 February 2024 (UTC)

Regarding climate niche, AR6 WG2 p.153:

"The rather narrow climatic niche favoured by human societies over the last 6000 years is poised to move on the Earth’s surface at speeds unprecedented in this time span (IPCC, 2021a), with consequences for human well-being and migration that could be profound under high-emission scenarios (Xu et al., 2020). This will overturn the long-lasting stability of interactions between humans and domesticated plants and animals as well as challenge the habitability for humans in several world regions (Horton et al., 2021) (medium confidence)."

I think something about climate niche should be mentioned in the article. Bogazicili (talk) 16:40, 4 February 2024 (UTC)

We would probably need to do a deep dive into all the heat stress/wet bulb literature at some point. Incredibly, I am not even sure if there is even a Wikipedia article which is the accepted go-to place to cover it? (Effects of climate change on human health seems like it might be the closest one.)

The main issue I found the last time I looked at the subject, is that there are actually multiple different metrics of heat stress, which appear to have only partial overlap, yet even the recent major studies can still use all of those. To show you what I mean:

• There is wet bulb temperature, which is the one our readers of a certain age are likely to be the most aware of, in large part "thanks" to The Ministry for the Future.
• There is the "mean annual temperature", which is what the human niche study used - the study cited by the IPCC in the quote you provided. (And is also the metric which had been at least partially questioned in a study published about 6 months after that IPCC report.)
• There is the Universal Thermal Climate Index, which is what had been used by Lyon et al. 2021. For the record, their graphic of 2100-2500 changes might be the single best illustration for this section, since my earlier food-related graphics have been rejected for one reason or another.
• And then, there are whatever calculations the "50% to 75%" study used to arrive at their figures, because it's certainly not any of the three above. These are just the papers I know of, and I wouldn't be surprised to find even more.

So, it's a fairly complex subject to work on. The reason why I REALLY don't like your "life-threatening due to combined effects of extreme heat and humidity" wording is because nowadays, a lot of readers will read that and think it refers to areas that will be subject to scenes like the opening of The Ministry for the Future (a depiction which appears to be about as accurate as The Day After Tomorrow). As opposed to well, the paper defining it as an area which can have heatwaves that will kill at least one person. Except, the paper is not even good at that, because by that logic Europe would also already be in that zone after 2003, but in the paper, it isn't.

If we can't think of a proper clarification, then just tossing that paper entirely and instead writing a sentence on any one of the studies which use less-confusing metrics might be the best possible solution. Even if we keep the mention of that study, the current wording is untenable. InformationToKnowledge (talk) 10:29, 5 February 2024 (UTC)

"Deaths will be caused by coastal flooding, childhood malnutrition, exposure to heat and humidity, and from increased transmission of infectious diseases such as malaria, diarrhea and dengue fever" is also problematic, because this is not an exhaustive list of death causes due to climate change. Those are just some of the factors cited in WHO estimate. But WHO estimate is not an exhaustive list of climate change deaths. I'm going to restore previous wording, until a consensus can be reached. Bogazicili (talk) 16:53, 4 February 2024 (UTC)

Again, some of the wording is worse than previous version. Eg: "This is expected to continue into the near future". This is so vague, and has bunch of sources cited. What is expected to continue? Greater farm productivity outweighing climate change losses? This is what world bank source says [1]:

" Lower crop yields and higher food prices. Modeling studies suggest that climate change could result in global crop yield losses as large as 5 percent in 2030 and 30 percent in 2080, even accounting for adaptive behaviors such as changed agricultural practices and crops, more irrigation, and innovation in higher yield crops (Biewald et al., forthcoming; Havlík et al., forthcoming). Over the short term, climate change will also create some benefits, but mostly in cold and relatively rich countries, while poorer regions will be the most negatively affected. The expected yield losses are likely to translate into higher agri cultural prices; and climate change will make it more difficult, even with more trade, to ensure food security in regions like Sub Saharan Africa and South Asia. In a world with rapid population growth, slow economic growth, and high GHG emissions (that is, a scenario in which global temperatures increase by approximately 4oC by 2100), food availability in these regions could pla teau at levels far below current levels in devel oped countries (figure O.2)."

Again, I'm restoring previous version. Bogazicili (talk) 17:16, 4 February 2024 (UTC)

So I reverted the text in that section to what it was before edits by InformationToKnowledge (which included my edits) and then Bogazicili. Here is what it was after edits by Bogazicili, which I do not like as it has major readability issues, including run on sentences and repeated information:

https://en.wikipedia.org/w/index.php?title=Climate_change&oldid=1203342399#Food_and_health

I'm fine with the substance of Bogazicili's concerns, but we need to come up with new text that incorporates them and is also readable. Let's try to get to consensus here before going live with edits. Efbrazil (talk) 21:52, 4 February 2024 (UTC)

Efbrazil, can you quote repeated information and run on sentences in that version? Your reversion seems to be not justified and lack adequate explanation. Also I found your edit summary weird. What was exactly unreadable [2]? Bogazicili (talk) 22:05, 4 February 2024 (UTC)

Here are my concerns with the text as it had become:

• The death issues are enumerated, then the same laundry list of issues are enumerated a second time in the WHO statement. There is no need for the redundancy there.
• The last 2 sentences of the first paragraph are both way too long to be readable and digestible.
• The old wording simply says "Childhood malnutrition", while the new wording pads the content with an entire extra sentence saying "Young children are the most vulnerable to food shortages".

While I could have tried to patch those things up, I think the text as it had become was worse than what we had previously. I just hope one of us can propose text here that we all agree to rather than thrashing on page. Efbrazil (talk) 22:21, 4 February 2024 (UTC)

Efbrazil, first of all, did you read what you reverted to? First and 3rd points are in the current version, which you reverted to. I had restored them to original earlier version myself. Bogazicili (talk) 22:26, 4 February 2024 (UTC)

The thing about the World Bank quote is that it appears to be calculating those losses relative to an ideal counterfactual future without climate change, as opposed to calculating them relative to the present day, which is what most people will immediately assume. Same goes for the IPCC "8 to 80 million people" estimate. Likewise, in the quote, "food availability in these regions could plateau at levels far below current levels in developed countries", the key word is developed. If you look at the figure on page 4, you'll see that the only scenario where the graph of food availability in Sub-Saharan Africa and Southeast Asia doesn't go up throughout the century is the one where there is both 4C climate change and CO2 fertilization effect does not work (and by now, we know well enough it does - see the figure in that article). Even then, it simply stays at about the same level as now. This is also confirmed by the Springmann paper in The Lancet, where most people only pay attention to the "~540,000 deaths" part, yet those at most offset a third of the lives which would be saved relative to now.

Granted, both the World Bank reference and the Springmann paper are from 2016. Out of what you called "a bunch of sources cited", the most recent one, from 2021, says the following:

Across five representative scenarios that span divergent but plausible socio-economic futures, the total global food demand is expected to increase by 35% to 56% between 2010 and 2050, while population at risk of hunger is expected to change by −91% to +8% over the same period. If climate change is taken into account, the ranges change slightly (+30% to +62% for total food demand and −91% to +30% for population at risk of hunger) but with no statistical differences overall.

It also makes a similar point in this figure (whose licensing appears prohibitive): under the extensive development pathways (the "perfect" SSP1, baseline SSP2 and even the "screw nature, extract everything to benefit all humans" SSP5), population at risk of hunger would greatly decline under all warming pathways, from lowest to highest. Under the "instability" pathway (SSP3) and the "rich countries prosper, poor suffer" pathway (SSP4), there is a chance the population at risk of hunger increases even in the complete absence of further climate change (NOCC).

Considering space limitations, this might be the best wording. (Bolded parts represent what I changed relative to what was recently reverted from the article.)

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. In 2019 (?), they assessed deaths from coastal flooding, childhood malnutrition, exposure to heat and humidity, and from increased transmission of infectious diseases such as malaria, gastroenteritic diarrhea and dengue fever. Between 2030 and 2050 these factors could be causing 250,000 additional deaths per year, particularly threatening children and the elderly. Days with high heat stress are unsuitable for outdoor work, and if the warming reaches 4 °C, then up to 250 days per year would become unsuitable in some tropical zones. [Additional sentence on heatwaves/heat stress here - either the one we had recently, or based on a completely different paper.]

Global fishery yields will decline as every degree of warming reduces total fish biomass. By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. Crop yields are already getting negatively affected by stronger heatwaves and water stress, but globally, this has been strongly outweighted by greater farm productivity. Between 2010 and 2050, the number of people at risk of hunger will be far more affected by socioeconomic developments than climate change. It is expected to increase by up to 30% if there is stagnation or major instability in the developing countries, and will decrease by hundreds of millions otherwise, substantially reducing annual deaths from malnutrition. Climate risks to agriculture increase after 2050 at higher warming levels. Out of areas currently used for agriculture and livestock rearing, a third may stop being usable by 2100 under high emission scenarios.

Reasoning for these changes: besides what I already mentioned above, I took into account the point that climate change can cause deaths in other ways too, and those were simply the ones WHO looked at during that year (probably 2019.) I also think it's important to clarify that "diarrhea" is not a disease "in and of itself", but it is often caused by various diseases which all cause inflammation known as gastroenteritis. For heat stress at 4C, the figure really applies to all outdoor work - it was reasonable to specify agricultural workers when it was in the paragraph on food, but not so much otherwise. What really should be specified instead is that 250 days was the upper limit which would apparently be limited to the most unlucky locations, not a blanket impact across all tropics. InformationToKnowledge (talk) 11:34, 5 February 2024 (UTC)

P.S. I would still like to talk about short-term shocks to food supply from (multiple) breadbasket failures somewhere in this section. That, and I would ideally like to mention CO2 fertilization effect, and the reductions in crop micronutrient content it causes/global micronutrient deficiencies it can cause, but I am not sure on how to fit both of those. Hopefully, it would become easier if the section on Causes is shrunk. InformationToKnowledge (talk) 12:11, 5 February 2024 (UTC)

InformationToKnowledge, I disagree with above changes, a lot of information is lost. You are suggesting a massive re-write without adequately explaining reasoning. Some of my objections:

1) Why did "Extreme weather leads to injury and loss of life," got taken out for example?

2) "Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria." and then the WHO numbers are not repetition. One is explaining why there is an increase, the other is giving a number. "dengue fever and malaria" as examples from the earlier sentence can be taken out however.

3) What happened to "By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity."?

3) Why did 8 to 80 million people at risk of hunger by 2050 got taken out? Yes, population at risk of hunger may "decrease by hundreds of millions otherwise" in total because a lot of countries do get more developed. Why is this more relevant rather than just looking effects of climate change? I mean you complained about baseline being "ideal counterfactual future without climate change, as opposed to calculating them relative to the present day". But why would you compare 2050 with present day without accounting for the development of countries? 8 to 80 million is a more simple number, because it isolates effects of climate change. However, I'm more open to this change after wording changes. Your wording didn't make it clear that upper limit rose from 8% to 30% due to climate change. It made it sound like " stagnation or major instability in the developing countries" was the only factor. Misleading.

4) Why did "30 to 50%" numbers got removed for labour capacity reductions? The source doesn't specify this is just for food workers, although previous sentence talks about it.

5) Why did "it has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010." got removed?

6) Second paragraph does not accurately reflect the World Bank Source above

You are suggesting massive re-write of a version that's been stables for years, and I do not see the rationale for change. Definite no. We can go over some sentences one by one, like the at risk of hunger sentence. But I'm disagreeing with the proposed wholesale change. Bogazicili (talk) 15:17, 5 February 2024 (UTC)

InformationToKnowledge, also, given how you are proposing these massive changes, going over them is very time consuming. Moving forward, would you mind making these big change suggestions in one of the following formats:

Talk:Climate_change/Archive_93#Lead's_description_of_the_greenhouse_effect

Talk:Climate_change/Archive_92#Mention_inequity_between_polluters_and_pollutees_in_the_lead

Talk:Climate_change/Archive_85#Need_to_reevaluate_recent_edits_to_first_two_mitigation_paragraphs

Basically including both the current version and your suggested change, and striking out removals and bolding additions. This is very helpful, and multiple editors used something like this when suggesting big changes. Bogazicili (talk) 16:38, 5 February 2024 (UTC)

I made a deeper revert to stable version, while talk page discussions go on. Just made 2 changes, which I don't think are controversial. Bogazicili (talk) 17:40, 5 February 2024 (UTC)

Firstly, it's unfortunate that you aren't following this discussion very closely, because a substantial fraction of the current suggested wording has been there after @Efbrazil edited my earlier proposals. See this revision. Efbrazil also signed off on my previous addition, which you reverted, so need to take up those questions with them as much as you do with me.

Essentially, about half of your questions can be answered very simply - because I keep getting told that we are running out of article space, so any real additions would have to come at the expense of something else. Thus, we need to condense and prioritize.

I'll address the basic points first, and then I'll show the revised text.

1) Why did "Extreme weather leads to injury and loss of life," got taken out for example? - Because it's an extremely general and a very obvious statement, which does not even have a real number attached to it. It does not add any real value to the collage in the lead showing wildfires as an example, to the "Climate change impacts on the environment" gallery showing the Australian wildfires and, most of all, to the Extreme weather figure from the IPCC directly above this section already showing a massive increase in extreme weather. If you really want to keep this wording, I would suggest moving it to that graphic's caption instead.

2) "Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria." and then the WHO numbers are not repetition. One is explaining why there is an increase, the other is giving a number. One of my proposed sentences literally says {tq|from increased transmission of infectious diseases}}. The fact that the climate is getting warmer is said so many times throughout the article that any reader who would have made it to this section does not need it spelled out again. Efbrazil also believes that readers can make this connection for themselves. And it's not even a good explanation either, since it does not say what increases transmission in a warmer climate.

3) [I] What happened to "By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity."? - It's potentially a sentence I placed in square brackets: [Additional sentence on heatwaves/heat stress here - either the one we had recently, or based on a completely different paper.] I wrote very detailed comment on why we may not want to cite that particular paper (which will be 7 years old this year) and instead use any one of the newer and better-defined papers in this revision.

3) [II] But why would you compare 2050 with present day without accounting for the development of countries? Because, this article is aimed for a general reader. Here a couple of relevant examples of the mindset of many general readers.

This section is an excerpt from Climate change and civilizational collapse § Public opinion.[edit]

Some public polling shows that beliefs in civilizational collapse or even human extinction have become widespread amongst the general population in many countries. In 2021, a publication in The Lancet surveyed 10,000 people aged 16–25 years in ten countries (Australia, Brazil, Finland, France, India, Nigeria, Philippines, Portugal, the UK, and the US): one of its findings was 55% of respondents agreeing with the statement "humanity is doomed".

In 2020, a survey by a French think tank Jean Jaurès Foundation found that in five developed countries (France, Germany, Italy, the UK and the US), a significant fraction of the population agreed with the statement that "civilization as we know it will collapse in the years to come"; the percentages ranged from 39% in Germany and 52% or 56% in the US and the UK to 65% in France and 71% in Italy.

The people who think this way do not expect there to be any real development of countries by 2050. Not acknowledging that these people now make up a significant fraction of our readers is tantamount to wilful blindness.

8 to 80 million is a more simple number, because it isolates effects of climate change. - Again, it's not simple when it relies on "common sense" assumed knowledge which potentially a majority of readers no longer possess. (If we assume that those ~52% of people from the UK/US who said civilization will collapse in that French poll are representative of English Wikipedia, which isn't the worst assumption to make.) Secondly, we already have both effects of climate change and effects of climate change on agriculture This overview article needs to give the most basic facts, which, in this case is the net effect here. The details relative to an ideal state are already present in effects of climate change on agriculture and they can stay there.

Why did "30 to 50%" numbers got removed for labour capacity reductions? Because I was repeatedly told that the article must stay under 9000 words, and I have already made some additions elsewhere that brought it closer to the limit, yet which I consider more necessary than this wording. (I.e. mentioning the Southern Ocean overturning circulation tipping point or the committed increase in ocean deoxygenation.) The article was at 8692 words before I started making edits. Before your reversions, it was at 8822 words. Now, it is at 8913 words. As I said, it seems like we might shorten it elsewhere quite a bit, but a few days ago, it didn't seem that way, so I had to compromise.

5) Why did "it has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010." got removed? Same reasons as in 3). a) this isn't effects of climate change on agriculture, where mentioning specific crops and dates is appropriate detail; b) it is very likely that declines occurred in other crops - those three are simply the ones we have the best data for; c) it does not specify how large the decline was, leading our readers to assume any number. d) it does not specify that this was relative to climate-free counterfactual; e) The new sentence, Crop yields are already getting negatively affected by stronger heatwaves and water stress conveys a similar amount of information (more in fact, as it explains what caused the reductions), while avoiding all of the issues above.

6) Second paragraph does not accurately reflect the World Bank Source above a) You haven't specified what exactly you meant; b) year 2021 Nature meta-analysis is a far more important source than the year 2016 World Bank report anyway.

More discussion of food and health

I wasn't aware of using table format for making comparisons, so there it is.

1st paragraph

Late January wording

The proposal (bolded parts are the most recent revisions)

....The WHO calls climate change the greatest threat to global health in the 21st century. Extreme weather leads to injury and loss of life, and crop failures to malnutrition. Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria. Young children are the most vulnerable to food shortages. Both children and older people are vulnerable to extreme heat. The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition. By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity.

....The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. In 2019 (?), they assessed deaths from coastal flooding, childhood malnutrition, exposure to heat and humidity, and from increased transmission of infectious diseases such as malaria, gastroenteritic diarrhea and dengue fever. Between 2030 and 2050 these climate-driven factors could be causing 250,000 additional deaths per year, particularly threatening children and the elderly. Days with high heat stress are unsuitable for outdoor work. If the warming reaches 4 °C, then up to 250 days per year would become unsuitable in some tropical zones, and their overall labour capacity will decline by 30 to 50%. [Additional sentence on heatwaves/heat stress here - either the one on the left, or based on a completely different paper.]

2nd paragraph

Late January wording

The proposal (bolded parts are the most recent revisions)

....Climate change is affecting food security. It has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010. Future warming could further reduce global yields of major crops. Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative. Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts. Climate change also impacts fish populations. Globally, less will be available to be fished. Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change

....Global fishery yields will decline as every degree of warming reduces total fish biomass. By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. Crop yields are already getting negatively affected by stronger heatwaves and water stress, but globally, this has been strongly outweighted by greater farm productivity. Between 2010 and 2050, the number of people at risk of hunger will be far more affected by socioeconomic developments than climate change. It can increase if there is stagnation or major instability in the developing countries - by up to 30% if these conditions occur under high emissions. This number will decrease by hundreds of millions otherwise, substantially reducing annual deaths from malnutrition. Climate risks to agriculture increase after 2050 at higher warming levels. Out of areas currently used for agriculture and livestock rearing, a third may stop being usable by 2100 under high emission scenarios, while fewer than 10% will under low emissions.

I would hope I have already adequately explained the reasons for these changes, but just in case:

• We don't really need to talk about latitudes in this high-level article (rather than the "effects of" one) if we can't even do it with certainty.

• Likewise, the sentence on areas which may stop being usable outright, with specific estimates, is far more important than the one on water stress, which gives too much attention to the obvious (dry areas will have more water stress? Who knew?) without providing specific numbers.

• 183 million figure is fairly bad, even besides the "present-day vs. ideal 2050" discussion. It comes from SROCC (now 5 years old), and I don't remember seeing it in the AR6, suggesting it got overwritten between then and now. Further, it does not provide a date, rendering it nearly useless.

InformationToKnowledge (talk) 19:50, 5 February 2024 (UTC)

Not commenting on content (which I'm sure you're right about). Can we try to keep paragraphs to around 100 words? Much longer paragraphs impede readability. There are so many numbers in that text too, so even I am getting lost in here. I really hope you take the feedback to heart that number-heavy text is not easy to digest, and that Wikipedia has a lot of non-academic readers. —Femke 🐦 (talk) 20:24, 5 February 2024 (UTC)

InformationToKnowledge, thanks for the response. Again, would you mind striking out parts that you suggest deleting? Again, the format is hard to keep track of.

1) You said "- Because it's an extremely general and a very obvious statement". We do put obvious statements here, this is an encyclopedia. We do not assume prior knowledge. High school kids might be reading this article. We do not jump directly to complicated stuff. Those are more appropriate for detailed subarticles. See Wikipedia:Featured article criteria and Wikipedia:Summary_style

2) Again, "various infectious diseases are more easily transmitted in a warmer climate" is the general science. WHO just looked at malaria, diarrhea and dengue fever. WHO 250k number does not include an exhaustive list of all infectious diseases that are more easily transmitted with warming climate. It's also not the place to explain the general science. I'd keep "Various infectious diseases are more easily transmitted in a warmer climate" (general science) and simply say " increases in diarrhea, malaria, dengue" in later sentence.

3) I disagree with your rationale. The current wording better represents what the sources say. We try to best represent what the sources say in this article. By your own admission, you seem more concerned about your own assumptions about what readers might think

(You said: "The reason why I REALLY don't like your "life-threatening due to combined effects of extreme heat and humidity" wording is because nowadays, a lot of readers will read that and think it refers to areas that will be subject to scenes like the opening of The Ministry for the Future (a depiction which appears to be about as accurate as The Day After Tomorrow" [3]).

See: Wikipedia:Verifiability

4) More about your own assumptions about "relevant examples of the mindset of many general readers". Sources usually compare future projections with a base case scenario, and that base case scenario is usually NOT today with nothing changing. However, we can do compare to today without Wikipedia:No original research, eg: "which currently affects 30% of the global population" [4]

5)The point that some decline has already occurred is very important. It also comes from IPCC. That also seems contrary to what you were claiming that it was offset by "greater farm productivity". If there are two conflicting reliable sources, both should be there. See: Wikipedia:Neutral point of view.

6)Again, your paragraph is misleading. Upper limit rose from 8% to 30% due to climate change. By upper limit, I mean the bolded ranges below:

"Across five representative scenarios that span divergent but plausible socio-economic futures, the total global food demand is expected to increase by 35% to 56% between 2010 and 2050, while population at risk of hunger is expected to change by −91% to +8% over the same period. If climate change is taken into account, the ranges change slightly (+30% to +62% for total food demand and −91% to +30% for population at risk of hunger) but with no statistical differences overall."

Upper limit change is solely due to climate change, not due to "stagnation or major instability in the developing countries". Although the authors do say "no statistical differences overall", however we also have the IPCC source giving numbers. Both needs to be included per Wikipedia:Neutral point of view. Bogazicili (talk) 20:45, 5 February 2024 (UTC)

Femke, sure will keep that in mind. Not making any suggestions yet, just wanted to outline my concerns about new suggestions with respect to Wiki policies. Bogazicili (talk) 20:45, 5 February 2024 (UTC)

Oh, and InformationToKnowledge, regarding your concerns about civilizational collapse surveys, you might want to instead address them in Climate_change#Public_awareness_and_opinion section. Put the information about public opinion polls, and then what the scientists say in that section maybe, instead of trying to edit the rest of the article trying to conform to a specific POV. Bogazicili (talk) 21:16, 5 February 2024 (UTC)

Bogazicili As you might have noticed, I am under multiple competing pressures here. I need to:

1. Add information which was absent from the section in spite of its undeniable importance. (The whole reason this is happening in the first place.)

1. Keep each paragraph small enough, as pointed out by Femke just earlier.

1. Keep entire article below 9,000 words.

With these pressures, trade-offs need to be made. I did what you suggested, and crossed out words/sentences to be removed in the old version - as well as bolding the new information to be added. Parts which are in quotes have been rephrased between the two versions.

Late January wording

The proposal

....The WHO calls climate change the greatest threat to global health in the 21st century. ~~Extreme weather leads to injury and loss of life, and crop failures to~~ "malnutrition". ~~Various~~ "infectious diseases are more easily transmitted" ~~in a warmer climate, such as~~ "dengue fever and malaria". "Young children are the most vulnerable to food shortages. Both children and older people are vulnerable to extreme heat". The World Health Organization (WHO) "has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition." ???By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity.???

....The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. In 2019 (?), "they assessed deaths from coastal flooding, childhood malnutrition, exposure to heat and humidity, and from increased transmission of infectious diseases such as malaria, gastroenteritic diarrhea and dengue fever. Between 2030 and 2050 these climate-driven factors could be causing 250,000 additional deaths per year, particularly threatening children and the elderly." Days with high heat stress are unsuitable for outdoor work. If the warming reaches 4 °C, then up to 250 days per year would become unsuitable in some tropical zones, and their overall labour capacity will decline by 30 to 50%. [Additional sentence on heatwaves/heat stress here - either the one on the left, or based on a completely different paper.]

2nd paragraph

Late January wording

The proposal (bolded parts are the most recent revisions)

....~~Climate change is affecting food security.~~ "It has caused reduction in global yields:" ~~of maize, wheat, and soybeans between 1981 and 2010.~~ "Future warming could further reduce global yields of major crops." ~~Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative. Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts.~~ "Climate change also impacts fish populations. Globally, less will be available to be fished." ~~Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change~~

...."Global fishery yields will decline as every degree of warming reduces total fish biomass." By 2050, global livestock headcounts could decline by 7-10%, as less animal feed will be available. "Crop yields are already getting negatively affected" by stronger heatwaves and water stress, but globally, this has been strongly outweighted by greater farm productivity. Between 2010 and 2050, the number of people at risk of hunger will be far more affected by socioeconomic developments than climate change. It can increase if there is stagnation or major instability in the developing countries - by up to 30% if these conditions occur under high emissions. This number will decrease by hundreds of millions otherwise, substantially reducing annual deaths from malnutrition. "Climate risks to agriculture increase after 2050 at higher warming levels." Out of areas currently used for agriculture and livestock rearing, a third may stop being usable by 2100 under high emission scenarios, while fewer than 10% will under low emissions.

As Femke has already pointed out, some of the wording I added in the last revision, in large part to address your concerns, is making some paragraphs too long, so at least one revision to cut some wording will be necessary. I have already written out the reasons for the changes I made in my previous message, so please ensure you check it before asking further questions.

Now...

1) and 2): When we are struggling with word counts, both within a paragraph and within an entire article, duplicative/explanatory wording is just less important than wholly new information. Like facts about the effects on livestock (completely absent in the older version) or about areas becoming unusable (much better and more concrete than the vague sentences about latitudes and water stress.) And as I said, the sentence on extreme weather & injury/loss of life can simply be moved to a caption of the extreme weather figure directly above it. If anything, more readers will see it there.

3 and 4): First and foremost, "which currently affects 30% of the global population" is NOT WP:OR by ANY means. It is taken directly from the Carbon Brief reference, which I have added in one of the revisions prior to the one you pointed to, yet which you had now removed with your reversions. That reference is also what provides explanations about what that paper actually means and why it's never been a particularly good citation.

Secondly, how can you possibly write we do not assume prior knowledge, and then immediately assume that all our readers know that Sources usually compare future projections with a base case scenario, and that base case scenario is usually NOT today with nothing changing? We are always making some assumptions about what our readers may or may not to know, particularly when struggling against word counts. The idea that our readers wouldn't understand extreme weather kills people without having it spelled out, yet would intuitively know that figures like "8 to 80 million" or "up to 183 million" are relative to a better future world and not relative to present seems bizarre.

Besides, even if we assume that most readers know that development will be doing a lot to improve food availability, we are still inherently making assumptions about how much they think/know it will improve if we don't spell out the numbers. Thus, it's just easier to write something closer to my wording in the first place. Like you said High school kids might be reading this article. The most reliable reference on the subject to date suggests that 55% of this approximate demographic thinks "humanity is doomed". That makes it fairly clear which base knowledge they are lacking.

5) The point that some decline has already occurred is very important. It also comes from IPCC. That also seems contrary to what you were claiming that it was offset by "greater farm productivity". - Unless I am misreading this, it seems like even you are getting caught up in the differences between what the present wording seems to say, and the reference's actual base case. I found the IPCC's reference, and it makes it very clear that the decline is again relative to a counterfactual world with no climate change, and that there has been an overall increase, which is what the globally, this has been strongly outweighted by greater farm productivity wording in my article is getting at.

From the abstract:

Here, we estimate the impacts of climate change on the global average yields of maize, rice, wheat and soybeans for 1981–2010, relative to the preindustrial climate. We use the results of factual and non-warming counterfactual climate simulations performed with an atmospheric general circulation model that do and do not include anthropogenic forcings to climate systems, respectively, as inputs into a global gridded crop model.

From a section near the end:

Although the present study assesses the impacts on the average yields for 1981–2010, our results have implications for the observed yield trends. Yield increases driven by technological improvements have been a predominant trend worldwide during the last half century. These increasing yield trends are common across the historical and non-warming crop simulations (Figure S3), as these trends have been driven to a greater degree by socio-economic factors than by climatic factors. Importantly, the estimated yield impacts in recent years are larger than those of previous years, because warming is the primary climatic driver of the estimated yield impacts (Figures 7 and 8). Therefore, when the estimated yield impacts are negative, the increasing yield trends have slowed down compared to those obtained under the non-warming conditions. When the impacts are positive, the increasing yield trends have accelerated relative to those obtained under the non-warming conditions.

And I don't know if this should be cited in the article, but this chart shows beyond doubt that the yields for those and other crops are larger now than they were in 1981. Hence, the negative effect was obviously offset.

6) Upper limit change is solely due to climate change, not due to "stagnation or major instability in the developing countries". I don't know if you looked at the 2021 paper's Extended Data Figure already, but I strongly suggest you do it now. That figure clarifies that any increases in hunger only have a chance to occur in the scenarios of instability (SSP3) and stagnation of the developing world (SSP4). 30% is at the upper end of an error bar for a scenario which combines stagnation (SSP-4) with very high emissions (RCP 8.5), with the median figure a much smaller increase. The same level of high warming (RCP 8.5) risks a lower upper-end increase in the instability scenario SSP3 (the median is no change), and produces large declines in the other scenarios.

Thus, socioeconomic changes are far more important than the 2010-2050 warming, according to the study. The wording in the suggested version reflects that. - Between 2010 and 2050, the number of people at risk of hunger will be far more affected by socioeconomic developments than climate change. It can increase if there is stagnation or major instability in the developing countries - by up to 30% if these conditions occur under high emissions. This number will decrease by hundreds of millions otherwise, substantially reducing annual deaths from malnutrition. This phrasing is probably too long now, but the bulk of it should certainly be kept.

Further, while it's going to be very difficult to explain this in the article, it should also be noted that this combination is extremely unlikely, because it effectively requires that massive quantities of fossil fuels are extracted and burnt every year (RCP 8.5), yet this somehow fails to benefit the developing world economically. When the IPCC uses RCP8.5 now, it's almost always in combination with SSP5 (massive fossil-fuelled development), since the developing countries would have to be the ones responsible for a huge bulk of the new coal pits/wells and new thermal power plants, cars, etc. - else there is no demand to produce those massive, continually accelerating emissions in the first place.

Finally, thanks for the suggestion about expanding the Climate_change#Public_awareness_and_opinion section. Unfortunately, it'll require at least 2-3 sentences, and I don't think I can add that until a similar amount is cut elsewhere in the article.InformationToKnowledge (talk) 07:07, 6 February 2024 (UTC)

References

InformationToKnowledge, the answer is long, I can't read or respond to all of it now. And you are simply repeating many of your suggestions. I also don't know why you aren't striking out parts you suggest to be deleted like this.

So we can try Wikipedia:Dispute resolution requests. I'm going to respond to some points only:

3 and 4): I know "which currently affects 30% of the global population" is not OR, that is what I had meant. And that was my suggestion too. It was in the version I changed before Efbrazil reverted.

Here's my suggestion for first paragraph. Additions are in bold:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[228] Extreme weather leads to injury and loss of life,[229] and crop failures to malnutrition.[230] Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria.[231] Young children are the most vulnerable to food shortages. Both children and older people are vulnerable to extreme heat.[232] The World Health Organization (WHO) WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to several selected causes of death. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition.[233] By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity, up from 30% currently affected by such conditions.

I only added "up from 30% " as a new number, but I had also deleted this [5] in that paragraph, so that should satisfy Femke with respect to not too many numbers in the paragraphs.

For the second paragraph, I need to go over the sources.

"Days with high heat stress are unsuitable for outdoor work. If the warming reaches 4 °C, then up to 250 days per year would become unsuitable in some tropical zones, and their overall labour capacity will decline by 30 to 50%" information is currently in Inequality section, it should stay there. Bogazicili (talk) 15:04, 6 February 2024 (UTC)

Sorry for dropping out of this discussion for a bit, I was busy IRL. To be clear, my concern is simply that we not thrash the page and come up with text that is readable and has consensus. I see Bogazicili is direct editing again, I will try to work with everyone that way, but if we start going in circles again then we need to revert and come back here. Efbrazil (talk) 17:45, 6 February 2024 (UTC)

InformationToKnowledge, looks like Efbrazil ignored the above discussion and changed the wording in first paragraph, please keep that in mind when responding to my above suggestion. Bogazicili (talk) 20:07, 6 February 2024 (UTC)

Sorry if I missed something- a lot has been said. What in particular did I do that's controversial? I thought the edits I did were pretty incremental and safe. Feel free to back something out if you disagree. Efbrazil (talk) 22:05, 6 February 2024 (UTC)

Efbrazil, btw, can you also fix your run-in sentence, given that you frequently complain about them:

Your edit [6]: "Heat stress can prevent labourers from working, and if warming reaches 4 °C then labour capacity in those regions could be reduced by 30 to 50%" Bogazicili (talk) 17:26, 9 February 2024 (UTC)

Fair enough, I broke it into 2 sentences and clarified that the labourers in question are outdoor. Efbrazil (talk) 19:17, 9 February 2024 (UTC)

InformationToKnowledge, for the "but globally, this has been strongly outweighted by greater farm productivity" part in your suggestion, can you provide a quote from the source ("IPCC AR6 WG2 2022, p. 727")? That was the source in this version [7]. I skimmed through that page, but couldn't find it. Can read more carefully tomorrow too, but a quote would be helpful. Bogazicili (talk) 23:40, 11 February 2024 (UTC)

That is information suggested first by InformationToKnowledge, so they should speak to it. My contribution above was mostly wordsmithing and focusing content. Efbrazil (talk) 17:31, 12 February 2024 (UTC)

@Efbrazil:, I know, that's why I had pinged InformationToKnowledge in my response above. But thanks for confirming you were ok with that suggestion without checking sources. Bogazicili (talk) 16:58, 13 February 2024 (UTC)

The statement is primarily true with exceptions for time frame and geographical area, so I wasn't fussing over the source at the time. I personally only check sources on content I don't write if I don't know the content to be true. You can go ahead and check sources on everything and good for you if you do. Efbrazil (talk) 17:49, 13 February 2024 (UTC)

@Efbrazil: nope, the overall paragraph was not correct or neutral. Bogazicili (talk) 18:55, 13 February 2024 (UTC)

I'll let you sort that with I2K. Efbrazil (talk) 19:00, 13 February 2024 (UTC)

Right, minor error: it was actually page 728. The quote is: Global yields of major crops per unit land area have increased 2.5- to 3-fold since 1960. Plant breeding, fertilisation, irrigation and integrated pest management have been the major drivers, but many studies have found significant impacts from recent climate trends on crop yield (high confidence) InformationToKnowledge (talk) 12:17, 13 February 2024 (UTC)

@InformationToKnowledge:, Ok, so this was your edit: Crop yields are already getting negatively affected by stronger heatwaves and water stress,[236] but globally, this has been strongly outweighted by greater farm productivity.[237] [8]. So that was WP:OR. Because while the productivity has increased, there is no information about the change in size of land area. Also, later in the page in WG2, it says this The combined effects of heat and drought decreased global average yields of maize, soybeans and wheat by 11.6%, 12.4% and 9.2%, respectively (Matiu et al., 2017).. So, nope, the productivity gain has not outweighed all negative effects. We can note productivity increase in another wording though. But your deletion of It has caused reduction in global yields of maize, wheat, and soybeans... part to ONLY add growing productivity [9] was biased.

Your next sentence says this:

This is expected to continue into the near future,[238][239][240][241] but climate risks to agriculture will increase substantially at higher warming levels.[242][243][82]

I also find that rather biased, since the first source p.4 says this:

Lower crop yields and higher food prices. Modeling studies suggest that climate change could result in global crop yield losses as large as 5 percent in 2030 and 30 percent in 2080, even accounting for adaptive behaviors such as changed agricultural practices and crops, more irrigation, and innovation in higher yield crops (Biewald et al., forthcoming; Havlík et al., forthcoming). Over the short term, climate change will also create some benefits, but mostly in cold and relatively rich countries, while poorer regions will be the most negatively affected. The expected yield losses are likely to translate into higher agri cultural prices; and climate change will make it more difficult, even with more trade, to ensure food security in regions like Sub Saharan Africa and South Asia. In a world with rapid population growth, slow economic growth, and high GHG emissions (that is, a scenario in which global temperatures increase by approximately 4oC by 2100), food availability in these regions could pla teau at levels far below current levels in devel oped countries (figure O.2)

So as early as 2030, we might see overall crop yield losses despite increasing productivity. I'll go over the remaining sources and make a suggestion for second paragraph this week. Bogazicili (talk) 16:58, 13 February 2024 (UTC)

@InformationToKnowledge: also, in your suggestion [10], there are several primary sources [11] [12] [13]. (or were you quoting from their lit review sections?) There's no need to use primary sources since there's a lot of research on climate change. Secondary sources such as IPCC or World Bank or this study you had added [14] are preferred. There was this primary study [15] before, but it was supported by this secondary source [16]. But that was taken out anyway after you pointed out the mistake (thanks for pointing that out btw). Bogazicili (talk) 19:44, 13 February 2024 (UTC)

@Bogazicili It is unfortunate that you appear to have overlooked much of what I wrote on this talk page to focus only on my past edits. It seems like I'll have to repeat myself again.

there is no information about the change in size of land area. Agricultural land area had been consistently increasing up until very recently. It might have peaked in the past decade because efficiency gains allowed for some it to be rewilded, at least for now, but it had been increasing up until then. My earliest rewrite (the one you can see at the start of "Food and health" heading on this talk page) actually phrased it as total crop yields to date have been increasing due to improved farming practices and agricultural expansion, but then @Efbrazil objected to that wording. If that is your main objection, this can be referenced rather easily.

Also, later in the page in WG2, it says this I am going to repeat my earlier suggestion that you should double-check the references in AR6 quotes before bringing them up. This is what their reference, Matiu et al., 2017 actually says:

Since the focus of this study was on year-to-year climate variability and not climate change, long-term trends in both crop yields and climate were removed, such that time is not a confounding variable anymore. Consequently, impacts of climate change on crop yields [78] or impacts of climate change on climate variability [9] could not be considered.

I.e. that paper compares warm and dry years with an average year. It is not about any increase in heat and drought caused by climate change. Thus, it is largely irrelevant here. I have already shown you this link before, but there it is again: a secondary source which proves beyond doubt that total crop yields have increased greatly. I guess I can add that reference in the latest edit once we agree on the wording.

So as early as 2030, we might see overall crop yield losses despite increasing productivity. - We have already talked about this. What makes you think that this entire paragraph refers to overall crop yield losses? Here are both of its references - Biewald and Havlík. Key quotes from those which prove that the paragraph doesn't, in fact, mean overall losses.

In all three regions under consideration (Middle East and North Africa, South Asia, and Sub‐Saharan Africa), the average yield of food crops decreases with climate change compared to no climate change

and

Food availability would decrease globally by 3% under the climate stabilization scenario compared to reference levels by 2030.

And once again, look at what figure 0.2 on the same page of the same source shows: a consistent increase in calorie availability throughout the century under all but a single scenario, where there is more of a plateau after 2030. (And that scenario of no CO₂ fertilization is now contradicted by more and more studies - see the latest research on fertilization's observed benefits.)

Lastly,

There's no need to use primary sources since there's a lot of research on climate change. Secondary sources such as IPCC or World Bank or this study you had added [14] are preferred.

I would have to disagree a little here. The World Bank reference in particular is now 10 years old, and it often cites 15-20 year old research. There are now whole new generations of both climate and agricultural models that were not available when that reference was written. Those differences are important - i.e. consider this reference, which explains how much they matter. I cite that paper in the agriculture article, but not here, because its abstract only gives detailed information on two major crops and even then inconsistently, so I don't know how to fit it effectively into this article, but I am open to suggestions. Likewise, Lyon et al., 2021 is genuinely groundbreaking, with no previous climate research considering such timescales in terms of their implications for agriculture. Unless a secondary reference which discusses its agricultural projections (the ones I have seen to date usually focus on its other projections about temperatures, humidity, etc.) is found, I strongly suggest keeping it. I am more open to disregarding Janssens et al. 2020 and Wing et al., 2021, but I would not make a final judgement until we approach more consensus on the text.

Finally, I have already admitted that at first, I was wrong about that study cited by NEJM. However, when considered in full, the study actually supports the point that there'll be less hunger by 2050. See this talk page revision. InformationToKnowledge (talk) 09:31, 14 February 2024 (UTC)

InformationToKnowledge, apologies for the delay in my response, I got sidetracked in other articles. Will respond this week. Bogazicili (talk) 22:22, 21 February 2024 (UTC)

Agreeing here with both @InformationToKnowledge and @Bogazicili: primary sources and old sources are both not ideal. Primary sources in particular lead to very verbose text. We have plenty of high-quality secondary sources published in the last 5 years. The five-year rule is something loosely described in WP:MEDDATE, and probably also useful here, at least for the more contested elements of the text. —Femke 🐦 (talk) 20:50, 18 March 2024 (UTC)

InformationToKnowledge, You said: Also, later in the page in WG2, it says this I am going to repeat my earlier suggestion that you should double-check the references in AR6 quotes before bringing them up. This is what their reference, Matiu et al., 2017 actually says: I appreciate how through you are, but for Wikipedia purposes, this doesn't work. Most of us do not have the time or expertise to check IPCC's sources and decide they misinterpreted it. IPCC reports are a reliable secondary source. However, if you find another reliable secondary source, that can also be added. If you don't trust me on this, you can check: WP:V. Anyway, I moved higher in WG2 to summary for policy makers or technical summary. Those are the parts where it gives a more executive summary, using a variety of sources. Here's my suggestion:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[229] Extreme weather leads to injury and loss of life.[230] Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria.[231] Crop failures can lead to food shortages and malnutrition, particularly effecting children.[232] Both children and older people are vulnerable to extreme heat.[233] The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to various selected causes. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition.[234] By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity,[235] which currently affects 30% of the global population.[17] [Days with high heat stress and labor are in below subsection] Climate change is affecting food security. Despite overall increase in agricultural productivity, climate change have reduced water and food security, and have curtailed agricultural productivity growth.[IPCC AR6 WG2 Summary for Policymakers p.9] Agricultural productivity was negatively affected in mid- and low-latitude areas, while various high latitude areas were positively affected. [IPCC AR6 WG2 Summary for Policymakers p.9] It has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010.[236] Global yields of maize, wheat, and soybeans have decreased.[source change: IPCC AR6 WG2 p.728]. Fisheries have been negatively affected in multiple regions.[IPCC AR6 WG2 Summary for Policymakers p.9] Future warming could further reduce global yields of major crops.[237] Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative.[238] Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts.[239] Climate change also impacts fish populations. Globally, less will be available to be fished.[240] Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change.[241] By 2050, climate change may affect tens to hundreds of millions of people in terms of undernourishment and nutrition-related diseases;[IPCC AR6 WG2 Technical Summary p. 60] change in population at risk of hunger may be positive or negative depending on several climate change and socioeconomic scenarios.(new meta-analysis study) Beyond 2040, there will be increasing risks to food and water availability, and human health.[IPCC AR6 WG2 Summary for Policymakers pp. 14-15].

So changes: 1) Reduces length in first paragraph. 2) gives context for heat and humidity ("which currently affects 30% of the global population") 3) Adds increase in agricultural productivity in second paragraph 4) Gives more executive summary in second paragraph, with mostly SPM and TS. 5) Incorporates study you found [18] 6) Might make further minor copy editing, and also will need to check against close paraphrasing again. Bogazicili (talk) 22:58, 25 February 2024 (UTC)

@Bogazicili The IPCC did not "misinterpret" anything. However, a misintepretation can well occur when a single sentence in the report is read on its own and out of context of the surrounding paragraphs. It seems like I'll have to remind you of this context.

Ortiz-Bobea et al. (2021) analysed agricultural total factor productivity (TFP), defined as the ratio of all agricultural outputs to all agricultural inputs, and found that, while TFP has increased between 1961 and 2015, the climate change trends reduced global TFP growth by a cumulative 21% over a 55-year period relative to TFP growth under counterfactual non-climate change conditions. Greater effects (30–33%) were observed in Africa, Latin America and the Caribbean (Figure 5.3). Climate variability is a major source of variation in crop production (Ray et al., 2015; Iizumi and Ramankutty, 2016; Frieler et al., 2017; Cottrell et al., 2019)(Table SM5.1). Weather signals in yield variability are generally stronger in productive regions than in the less productive regions (Frieler et al., 2017), where other yield constraints exist such as pests, diseases and poor soil fertility (Mills et al., 2018; 5.2.2). Nevertheless, yield variability in less productive regions has severe impacts on local food availability and livelihood (high confidence) (FAO, 2021).

Climate-related hazards that cause crop losses are increasing (medium evidence, high agreement) (Cottrell et al., 2019; Mbow et al., 2019; Brás et al., 2021; FAO, 2021; Ranasinghe et al., 2021). Drought-related yield losses have occurred in about 75% of the global harvested area (Kim et al., 2019b) and increased in recent years (Lesk et al., 2016). Heatwaves have reduced yields of wheat (Zampieri et al., 2017) and rice (Liu et al., 2019b). The combined effects of heat and drought decreased global average yields of maize, soybeans and wheat by 11.6%, 12.4% and 9.2%, respectively (Matiu et al., 2017). In Europe, crop losses due to drought and heat have tripled over the last five decades (Brás et al., 2021), pointing to the importance of assessing multiple stresses. Globally, floods also increased in the past 50 years, causing direct damages to crops and indirectly reduced yields by delaying planting, which cost 4.5 billion USD in the 2010 flood in Pakistan and 572 million USD in the 2015 flood in Myanmar (FAO,2021).

So, this sentence is inside a paragraph where the preceding sentences talk about heatwaves and drought reducing yields in general. The previous paragraph has a sentence which specifically mentions "climate variability" - the annual differences between years with heatwaves and drought (or floods) and good agricultural years. Even if we forget about the text of the primary reference, a major hint that it does not refer to effects of climate change specifically is that these figures are undated. Basically every single time when the IPCC uses numbers to describe the actual impacts of climate change, it provides a baseline - i.e. "increased in the past 50 years" in the following sentences.

Nevertheless, all of this is semantics when compared to the most definitive argument.

However, if you find another reliable secondary source, that can also be added.

I did, and I provided it twice, in my comments on the 6th and 14th February. I'll link it again; please do not make me do this for the fourth time!

Now, here is my edit of your proposal.

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[229] Extreme weather leads to injury and loss of life.[230] Crop failures can lead to food shortages and malnutrition, particularly effecting children.[232] Both children and older people are vulnerable to extreme heat. The WHO It has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to various selected causes impacts such as increased levels of extreme heat, greater frequency of extreme weather and changes in disease transmission. Lethal infectious diseases such as dengue fever and malaria are more easily transmitted in a warmer climate.[231] By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity, which currently affects 30% of the global population. 30% of the global population currently live in areas where extreme heat and humidity can be potentially lethal, (CB reference) particularly to children and the elderly.[233] By 2100, 50% to 75% of the global population would live in such areas.[235] Despite overall increase in agricultural productivity, climate change have reduced water and food security, and have curtailed agricultural productivity growth. Agricultural and socioeconomic changes had been increasing global crop yields since the middle of the 20th century, [Our World in Data reference] but climate change has already slowed the rate of yield growth.[IPCC AR6 WG2 Summary for Policymakers p.9] Agricultural productivity was negatively affected by climate change in mid- and low-latitude areas, while various high latitude areas were positively affected and positively at high latitudes. [IPCC AR6 WG2 Summary for Policymakers p.9] Global yields of maize, wheat, and soybeans have decreased. Fisheries have been negatively affected in various regions.[IPCC AR6 WG2 Summary for Policymakers p.9] Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change.[241] By 2050, climate change may affect tens to hundreds of millions of people in terms of undernourishment and nutrition-related diseases; change in population at risk of hunger may be positive or negative depending on various climate change and socioeconomic scenarios. By 2050, the number of people suffering from undernourishment and the associated health conditions is likely to decrease by tens to hundreds of millions, but some combinations of severe climate change and low socioeconomic development may increase that number instead. (2021 meta-analysis) By 2050, global livestock headcounts could decline by 7-10% under 2C of warming, as less animal feed will be available.[IPCC AR6 WG2 p.748] Extreme weather events adversely affect both food and water security, and climate change increases their frequency.[IPCC AR6 WG2 Summary for Policymakers p.9][230] Beyond 2040, there will be increasing risks to food and water availability, and human health.[IPCC AR6 WG2 Summary for Policymakers pp. 14-15]. If the emissions remain high, food availability will likely decrease after 2050 due to diminishing fisheries and livestock counts, and due to more frequent and severe crop failures.[IPCC AR6 WG2 p.797]

Explanation for the changes:

1) I still don't like that we mention the WHO in the first sentence of the paragraph, then have three vaguely connected sentences, and then we mention the WHO again. This structure should make it clearer that the really vague "various selected causes" actually refers to extreme heat, extreme weather and disease transmission specifically. I decided to add "Lethal" to the sentence about malaria and dengue fever to underline the same point.

2) I also don't like how the paragraph first mentions extreme heat in its third sentence, then mentions other things, then jumps back to extreme heat at the end. Thus, I combined mentions of extreme heat into a single sentence.

3) "Agricultural productivity" is a somewhat vague and academic wording, so I used the simpler and more easily understood phrase, backed up by the OWID reference. Moved the phrase about food and water security a few sentences lower to improve paragraph flow.

4) Simplified the wording (and hopefully reduced close paraphrasing as well) in the sentence on latitudes.

5) Since we know that the sentence on the "decrease" in yields for those three crops misread the reference, I have removed it.

6) I removed the sentence on glacier water and small islands, because reference 241 is that awful thing which happens on Wikipedia sometimes - two disparate references jammed into one. One of those is a primary source from 2016, and the other one is AR5. I suggest writing another sentence on water scarcity based on AR6 specifically, without trying to retain this wording.

7) The sentence on changes by 2050 is both really hard to parse and is far too non-committal, suggesting uncertainty where it doesn't exist. We shouldn't be afraid of summarizing what the references as a whole actually say.

8) Re-added a sentence on changes to livestock by 2050, because there is no reason to neglect them.

9) Clarified that the WG2 SPM primarily meant impacts on food and water security from extreme weather events.

10) It doesn't make sense to suddenly mention the 2040 baseline after the rest of the section (and of the article) uses 2050, simply because of WG2 SPM (and only SPM). It also doesn't really make sense to mention health again at the end of a paragraph focused on food up until this point. Replaced that sentence with one summarizing likely impacts on food production after 2050 based on WG2. InformationToKnowledge (talk) 14:50, 27 February 2024 (UTC)

@InformationToKnowledge: You said: I did, and I provided it twice, in my comments on the 6th and 14th February. I'll link it again; please do not make me do this for the fourth time!

Sorry about that! I don't always read all of your responses in full given their length. I see maize, wheat, and soybeans seem stable here [19], so we can drop that line ("Global yields of maize, wheat, and soybeans have decreased").

1) It's vague because it should be. Your version says "changes in disease transmission". This is incorrect. WHO only looked at:

Compared with a future without climate change, the following additional deaths are projected for the year 2030: 38 000 due to heat exposure in elderly people, 48 000 due to diarrhoea, 60 000 due to malaria, and 95 000 due to childhood undernutrition

So they didn't look at ALL diseases. They only looked at diarrhoea, malaria and dengue (see page 4). Your suggested wording "changes in disease transmission" is a massive misrepresentation. There might be much more serious consequences of climate change when it comes to disease transmission [20]. Even US army is worried about that [21]

The vague wording is also to save space.

2) Opening sentences give general info.

3) I don't think it's academic. And I also don't like how you are shifting focus. This article is not Agriculture. If it were, a general sentence about increasing global crop yields would be perfectly ok. But this article is about climate change. Of course global crop yields have been increasing since 1960's. First of all world population is much greater. Tech is more advanced. And we haven't seen the worst of climate change effects yet. My suggestion was shifting the focus back to climate change.

4) You generalized. Was it positively affected at all high latitudes? What's a "high latitude" since you strengthened the wording now?

5) Ok, this is good

6) Water scarcity based on AR6 is fine.

7) Of course uncertainty always exists. These are models with bunch of inputs. The results give a range with a certain probability. There's always a probability that numbers outside the range can happen, even if assumptions and inputs of the model are correct. I am open to revising this sentence though

8) Too many numbers

9) Where does it say that?

10) There is no "baseline". We are reporting current, near term, mid term and long term effects. "By 2100" and "after 2040" are long term effects.

If you fundamentally disagree with above, and if there are no more comments from other editors, I'd suggest moving further in Wikipedia:Dispute_resolution_requests. Given this is a complicated issue with bunch of sources, I wouldn't recommend an RFC. I'd recommend Wikipedia:Dispute resolution noticeboard. If you don't fundamentally disagree, I can make another suggestion later this week. Bogazicili (talk) 18:08, 4 March 2024 (UTC)

1) If the WHO did not look at a disease in the first place (i.e. it didn't have the data for it or didn't find the changes would be important) then it is effectively irrelevant in a sentence that is about the WHO estimate only, as we already say very clearly. We do not by any means imply that their estimate is already perfect or that it has had time to look at everything.

1.1) I actually wrote our article on that particular subject last year, Pathogenic microorganisms in frozen environments. It's a really sensationalized subject, and if you want to be consistent and use only reliable secondary sources, then the one review I found is largely dismissive of the idea. If you want to include a sentence to summarize a conclusion like

To date, there is no report of intact and infectious RNA viruses directly isolated from permafrost. Therefore, although RNA viruses can be preserved in permafrost, based on our current knowledge, the risk of these RNA viruses being infectious to humans or other animals is unlikely.

Or

As we have summarized in this review, although some of the microorganisms and viruses that are preserved in permafrost can be active after thawing, the risks to human health are generally low.

you can, as we should now have enough space for it, but would there be a point?

2 + 3) Exactly, and telling readers that crop yields have been increasing to date is general info, one which readers are much less likely to know than the bland "extreme weather kills people". In fact, the IPCC itself also considers it important to refer to this (see even the next sentence).

4) Better question: do we really need this sentence at all, in any way? In fact, I took it out earlier, but then you decided to re-add it. My issue is that your proposed wording just does not read well - while various high latitude areas were positively affected is just messy and completely unclear how much or little "various" means. Granted, the original IPCC wording - Although overall agricultural productivity has increased, climate change has slowed this growth over the past 50 years globally, related negative impacts were mainly in mid- and low latitude regions but positive impacts occurred in some high latitude regions is also vague, which highlights my point. Why do we need to mention latitudes in a top-level article if we cannot devote enough space to adequately explain what we mean? Consumers don't care which latitude their food comes from, and farmers can look at a sub-article.

7) Your proposed wording basically suggested scientists have no idea which direction it's most likely to go, when the models, reviews, etc. are fairly clear about the direction and the conditions it would take to upend it. You also really seem to overuse the word "various", which is almost never helpful if you can have more precise alternatives. That was my point.

8) I am open to replacing "under 2C of warming" with "under high warming", since 2C by 2050 only occurs in the high-warming scenarios. I don't think we should change anything else, or avoid including this sentence.

9) Climate change including increases in frequency and intensity of extremes have reduced food and water security + Increasing weather and climate extreme events have exposed millions of people to acute food insecurity and reduced water security + Jointly, sudden losses of food production and access to food compounded by decreased diet diversity have increased malnutrition in many communities - all of it in the same paragraph on this page. It's very clear it intends a special focus on weather extremes.

10) My point was that basically every other relevant reference we cite throughout this article chooses 2050 as the comparison year for this timeframe (including the relevant passage in AR6 WG2) and only WG2 SPM uses 2040 (and it doesn't seem to have anything like the wording you suggested either.) We should avoid confusing readers with inconsistency.

Lastly, my experience with these Wikipedia mechanisms so far has been that it takes a lot of time, and they often punt on the issue anyway. Granted, I have not tried DRN yet, but my preference would be to ask the editors active on this very page (i.e. @Efbrazil, @EMsmile, @Femke, @RCraig09, @Uwappa) for input before we involve these protracted mechanisms. InformationToKnowledge (talk) 06:07, 5 March 2024 (UTC)

I agree with I2K that we don't need to invoke one of those formal Wikipedia mechanisms yet. There should be enough of us good-willed and skillful editors here to find a solution. I currently don't have the bandwidth to involve myself in depth. In general, I find I2K's work and content very good although sometimes written in a bit of an "academic" style (long sentences / literature review style) - a lot of us with a uni background in science suffer from that. ;-)

For the climate change article here, my suggestion would be to keep the content on food security and health issues really brief and point our readers to the sub-articles effects of climate change on agriculture and effects of climate change on human health at the earliest opportunity. And then ensure that those sub-articles, especially their leads, are really perfect and up to date. We could then use the same sentences here and in the leads there (in the absence of using excerpts).

I find that our important CC sub-articles deserve more attention and sometimes we spend too much time on this main CC article and not enough time on those sub-articles. EMsmile (talk) 09:19, 5 March 2024 (UTC)

@EMsmile:, InformationToKnowledge also said we should not include certain information because it says "after 2040", which would be confusing to readers because we said "by 2050" in another sentence. I mean this is ridiculous. Also this discussion has been going on for over a month. So yes, as I said, unless more editors provide input, we should proceed to dispute resolution noticeboard.

I'm assuming no one will bother to read the entire conversation, so if anyone wants to jump in, I'd suggest looking at the last 2 yellow boxes. Bogazicili (talk) 10:28, 5 March 2024 (UTC)

To clarify: your suggestion was to replace a proposed sentence which discussed impacts after 2050 with a less detailed sentence which had similar phrasing but said "after 2040", apparently only because you felt that the AR6 WG2 SPM would be a better reference than a chapter of AR6 WG2.

I concur that the last two yellow boxes are the most important parts, however. InformationToKnowledge (talk) 10:39, 5 March 2024 (UTC)

The section name is "Food and health". "Beyond 2040, there will be increasing risks to food and water availability, and human health.[IPCC AR6 WG2 Summary for Policymakers pp. 14-15]." is a better and more concise concluding sentence, especially since there are issues we haven't covered in this section [22] Bogazicili (talk) 10:54, 5 March 2024 (UTC)

If there are issues we haven't covered in this section then...that's an argument for rescoping the section? Besides, the only mention of 2040 on the pages you are citing is Beyond 2040 and depending on the level of global warming, climate change will lead to numerous risks to natural and human systems. You are then apparently combining that wording with some material from paragraphs B.4.3 and B.4.4 to arrive at your chosen wording (while omitting the bolded part - arguably "misrepresentation" by your own standards). I just think that it is much cleaner and less confusing when the section first cites a projection up until 2050, then starts talking about what could happen after 2050.

I should also mention there is no objective reason to keep the section named "Food and health" anyway. We could just as easily retitle the first paragraph "Human health" and the second "Food and agriculture", and then the rationale for combining the two in one sentence goes away entirely. InformationToKnowledge (talk) 11:32, 5 March 2024 (UTC)

If you are proposing to reorganize entire Humans section, it'd probably take a year with the speed this is going. And we can definitely add rephrased version of "and depending on the level of global warming". To borrow your phrase, I thought it was "a very obvious statement". You are suggesting we delete "Extreme weather leads to injury and loss of life" part because it's too obvious, but I guess CDC didn't think so. [23] There's also no objective standard why you thought it was too obvious to add, but you still suggested "Extreme weather events adversely affect both food and water security"? Oh and one paragraph sections would be too short. That's an objective reasons, at least for Wikipedia. Bogazicili (talk) 12:08, 5 March 2024 (UTC)

OK, it's been 5 days, and still nobody else here is willing to simply compare two versions of a two-paragraph section here and express their opinion. Would we really have to move to DRN after all? If not, then how much longer must we wait? InformationToKnowledge (talk) 14:50, 10 March 2024 (UTC)

where exactly is the comparison table that we are meant to review? Is it the table that I can find when scrolling up? I suggest to add a new section heading here and then repeat (or summarise) what the current question or comparison is. Sorry if this is annoying but I fear people switch off or give up following after a while when they see two people discussing something for a long time. EMsmile (talk) 23:39, 10 March 2024 (UTC)

Additional discussion of food and health

@EMsmile: here's my updated suggestion based on the new sources [24] (see the chart at the bottom) and [25]. Also added rephrased "and depending on the level of global warming" to the last sentence after InformationToKnowledge's suggestion. Keep in mind this is not the final suggestion. Might include minor copy editing, and also will need to check against close paraphrasing again.

Additions are bolded. Deletions are struck:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. [229] Extreme weather leads to injury and loss of life.[230] Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever and malaria.[231] Crop failures can lead to food shortages and malnutrition, particularly effecting children.[232] Both children and older people are vulnerable to extreme heat.[233] Extreme weather events affect public health.[26] Temperature extremes lead to increased illness and death.[27]Lancet The 2022 report Climate change can affect transmission of infectious diseases.[28] Lancet Editorial The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to increases in diarrhea, malaria, dengue, coastal flooding, childhood malnutrition, and heat exposure in elderly people. They assessed deaths from heat exposure in elderly people, increases in diarrhea, malaria, dengue, coastal flooding, and childhood malnutrition.[234] By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity,[235] which currently affects 30% of the global population.[29] [Days with high heat stress and labor are in below subsection]

Climate change is affecting food security. Despite overall increase in agricultural productivity, climate change has reduced water and food security, and have curtailed agricultural productivity growth.[IPCC AR6 WG2 Summary for Policymakers p.9] Agricultural productivity was negatively affected in mid- and low-latitude areas, while various high latitude areas were positively affected. [IPCC AR6 WG2 Summary for Policymakers p.9] It has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010.[236] Fisheries have been negatively affected in multiple regions.[IPCC AR6 WG2 Summary for Policymakers p.9] Future warming could further reduce global yields of major crops.[237] Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative.[238] Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts.[239] Climate change also impacts fish populations. Globally, less will be available to be fished.[240] Regions dependent on glacier water, regions that are already dry, and small islands have a higher risk of water stress due to climate change.[241] By 2050, climate change may affect tens to hundreds of millions of people in terms of undernourishment and nutrition-related diseases;[IPCC AR6 WG2 Technical Summary p. 60] change in population at risk of hunger may be positive or negative depending on several climate change and socioeconomic scenarios.(new meta-analysis study) Depending on climate change trajectories, there will be increasing risks to food and water availability, and human health beyond 2040.[IPCC AR6 WG2 Summary for Policymakers pp. 14-15].

Also I don't think there's any reason to be sceptical about Wikipedia:Dispute resolution noticeboard. I think it'd be more efficient with less back and forth. Bogazicili (talk) 16:36, 11 March 2024 (UTC)

Btw, my suggestion now has a word count of 231 vs the current 243. Bogazicili (talk) 16:58, 11 March 2024 (UTC)

Is this the same suggestion that InformationToKnowledge would put forward, or is the problem that both of you have different preferred versions that you're putting forward? Also, when you made the proposed changes, did you keep in mind reading ease aspects? E.g. this is perhaps using unnecessarily complex words: Climate change is projected to adversely impact water-related illnesses. Or perhaps the argument is: let's agree on content first and do the wordsmithing later? EMsmile (talk) 21:44, 11 March 2024 (UTC)

@EMsmile: exactly, let's agree on content first (something about water-related illnesses there), and then we can agree on exact wording. Bogazicili (talk) 21:29, 12 March 2024 (UTC)

Yes, the whole issue is that tend to disagree on every other sentence, so there have been about three waves of differing proposals from either of us by now. I have hidden the discussion about those three by now, so that the other editors can still click on the boxes to read them, but would otherwise focus their attention on the latest proposals for the section. You can see Bogazicili's proposal above, and my proposal is here. Since the former proposal already shows the original's section text in the struck-out sections, I decided not to duplicate that, and only to bold the writing that is mine:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. It has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to impacts such as increased levels of extreme heat, greater frequency of extreme weather and changes in disease transmission. Lethal infectious diseases such as dengue fever and malaria are more easily transmitted in a warmer climate.[231] 30% of the global population currently live in areas where extreme heat and humidity can be potentially lethal, (CB reference) particularly to children and the elderly.[233] By 2100, 50% to 75% of the global population would live in such areas.[235]

Agricultural and socioeconomic changes had been increasing global crop yields since the middle of the 20th century, [Our World in Data reference] but climate change has already slowed the rate of yield growth.[IPCC AR6 WG2 Summary for Policymakers p.9] Fisheries have been negatively affected in various regions.[IPCC AR6 WG2 Summary for Policymakers p.9] By 2050, the number of people suffering from undernourishment and the associated health conditions is likely to decrease by tens to hundreds of millions, but some combinations of severe climate change and low socioeconomic development may increase that number instead. (2021 meta-analysis) By 2050, global livestock headcounts could decline by 7-10% under higher warming, as less animal feed will be available.[IPCC AR6 WG2 p.748] Extreme weather events adversely affect both food and water security, and climate change increases their frequency.[IPCC AR6 WG2 Summary for Policymakers p.9][230] If the emissions remain high, food availability will likely decrease after 2050 due to diminishing fisheries and livestock counts, and due to more frequent and severe crop failures.[IPCC AR6 WG2 p.797]

Basically, these are the main things we have been arguing about for the past two months or so, and what the rest of editors here can hopefully decide on without invoking outside mechanisms:

1) We both agree that the WHO's mortality increase should be mentioned in the first paragraph, but how much detail to devote to each cause? You can see that Bogazicili favours more writing there, and I favour less. I find that sentences like "Extreme weather events affect public health. Temperature extremes lead to increased illness and death..." are too general and colourless to be of much use, and phrasing like "transmission risk of various diseases...Climate change is projected to adversely impact water-related illnesses." is outright confusing. I also find that mentioning WHO's words once, then writing several general sentences, then doubling back to WHO with a sentence running through each cause is outright duplicative at times.

2) Best way to phrase the sentence which discusses that finding on "life-threatening conditions" and extreme heat/humidity. You can probably just compare the two versions.

3) How explicitly to note that crop yields, etc. have been increasing to date? I also use "Extreme weather events adversely affect both food and water security" later in the article instead of "climate change has reduced water and food security" in Bogazicili's proposal, because I both find it closer to the reference, and because the other wording is unclear. "climate change has reduced water and food security" relative to what? A specific year in our recent past, or a counterfactual where climate change has not been happening? If we can't explain a particular wording in the paragraph text, we should not use it.

4) Do we need to talk about latitudes in this particular article, as opposed to the sub-articles? I would say that when the wording is as vague as "various high latitude areas", it's best not to bother.

5) Do we need to mention livestock, a massively important part of food production in many countries? I believe so, but Bogazicili is apparently unconvinced.

6) How explicit should we be about projections for mid-century? I find that Bogazicili's wording is far too confusing for this article and does not properly represent the reference chosen, as opposed to my wording.

7) How to talk about food security, etc. in the second half of the century? One issue we have been arguing is that Bogazicili chooses to use 2040 because WG2 SPM is separated into near-term (2022-2040) and 2040-2100 sections, but almost everything else uses 2050, including the relevant chapter of WG2. However, there have been other disagreements, as you can probably tell from the differences in wording.

I find that these are the 7 main questions other editors should comment on. InformationToKnowledge (talk) 17:45, 12 March 2024 (UTC)

@InformationToKnowledge: again, no reason to omit opening sentences such as "Extreme weather events affect public health" etc. For the end of the second paragraph, higher up pages in IPCC AR6 WG2 like in Summary for Policymakers give better overview, as it is a summary for non-science people. Pages 14-15 is preferable to going to page 797.

For the first paragraph, I'll agree to your wording for the part starting with "30% of the global population currently..." (we can drop "particularly to children and the elderly") if you agree with my suggestion until that part of the first paragraph. Bogazicili (talk) 21:35, 12 March 2024 (UTC)

Perhaps to just step back a little bit:

• how many paragraphs do we envision this section to have? How much space do we allow?
• And would it perhaps be helpful to split the section "food and health" into two separate sections? I think they ought to be separate and then both refer to their respective main article. For the food section (which might be better termed "food security"?), it would be effects of climate change on agriculture and effects of climate change on livestock, and for the health section it would be effects of climate change on human health.
• A side benefit of this approach would be that it would encourage us to improve those three sub-articles as well, or to at least look at them! Short of using excerpts from them (as excerpts are frowned upon for featured articles) we could at least ensure that they match up fully with their content (i.e. nothing in the main article that is not also in the sub-article). Most of the detailed numbers should only be in the sub-articles, not in the main article, in my opinion. EMsmile (talk) 21:43, 12 March 2024 (UTC)

It's only 2 paragraphs. The formatting might make it look longer (with the striking). My suggestion is 231 words, shorter than the current version here Climate_change#Food_and_health. Bogazicili (talk) 21:54, 12 March 2024 (UTC)

EMsmile, I modified my suggestion and included a new source [30]. The older source we had ("The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate") doesn't seem very accessible as it directs to the entire issue. It's open access but hard to find what you are looking for and verify information. Bogazicili (talk) 22:09, 12 March 2024 (UTC)

Hmmm, but what do you think of my suggestion to split it into two sections? Wouldn't that help to address this and to achieve greater clarity? They are really two different issues. Not all health issues are food related (only nutrition is). I don't see why they have to be lumped together. I would envision two paragraphs for food/crops/agriculture, and two paragraphs for health. Keep in mind that we will likely gain some space once we finally have the causes of climate change sub-article and can move some content from the "causes" section to there. EMsmile (talk) 22:40, 12 March 2024 (UTC)

I have also proposed splitting the sections in the "third phase" of discussion up above. One issue, though, is that Bogazicili insists on only using the secondary sources to reference this section. I don't think is a requirement even for a FA articles, but if it is, that could be quite limiting if we want to go from two paragraphs to four. InformationToKnowledge (talk) 05:08, 13 March 2024 (UTC)

A bold alternative: try an inverted pyramid. Recommended reading: Inverted Pyramids in Cyberspace, Jakob Nielsen, 1996. First step: try to agree on just 2 sentences that summarize the whole chapter. My suggestion, based on current text:

• An additional 183 million people are at risk of hunger.
• By 2100, 50% to 75% of the global population may face life-threatening conditions.

Once you agree on such a core, add more detail. Uwappa (talk) 08:25, 13 March 2024 (UTC)

It's not that simple. I would say that for the first paragraph, both of us already agree that the WHO "250,000 extra deaths" figure is the core summary, but it doesn't help us agree on the best way to follow it up with explanatory detail. With the "50% to 75%" figure, we agree on most of the phrasing, but not on how to explain the remarkably broad manner in which it defines "life-threatening".

And the 183 million figure is actually something both of us agreed to move away from, because it is defined relative to a hypothetical future without climate change, and not relative to the present as most people would assume. This makes it needlessly confusing and the way it's currently used in the article is arguably misleading. The more up-to-date reference (2021 vs. 2019) explicitly notes that relative to the present, the number of people at risk of hunger would decrease in many scenarios, but we are still arguing over the best way to phrase that. InformationToKnowledge (talk) 08:46, 13 March 2024 (UTC)

Please shift your focus from example text to a different approach. How can the two of you cooperate after weeks of discussion?

Are you willing and able to turn text around, start with the conclusion? Suggestion:

1. create a sandbox where the two of you can cooperate
2. start with just 2 core sentences. Agree on those 2 core sentences first. Celebrate your agreement!
3. take it from there, add more detail.

My hope: Once the two of you agree on 2 core sentences, adding detail will be relatively easy. Uwappa (talk) 09:46, 13 March 2024 (UTC)

@Uwappa: I had already offered a compromise to InformationToKnowledge [31], but InformationToKnowledge doesn't seem to want to compromise.

Here's the compromise text for the first paragraph. The bolded parts are InformationToKnowledge's wording (with "particularly to children and the elderly" taken out):

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[32] Extreme weather events affect public health.[33][34] Temperature extremes lead to increased illness and death.[35][36] Climate change can affect transmission of infectious diseases.[37] [38] The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to increases in diarrhea, malaria, dengue, coastal flooding, childhood malnutrition, and heat exposure in elderly people.[39] 30% of the global population currently live in areas where extreme heat and humidity can be potentially lethal.[40] By 2100, 50% to 75% of the global population would live in such areas.[41]

Bogazicili (talk) 22:15, 13 March 2024 (UTC)

@Uwappa: and @EMsmile: another issue is that InformationToKnowledge sometimes seems to want to play down effects of climate change because he is concerned about our readers freaking out too much ("Here a couple of relevant examples of the mindset of many general readers." [42]) I can see that mindset here Talk:Effects_of_climate_change_on_human_health#Article_appears_too_large_and_unwieldy_to_be_usable. Bogazicili (talk) 22:43, 13 March 2024 (UTC)

Please avoid dragging implications about other editors' mindset into content disputes. For anyone who hasn't looked at the diff or observed the discussion at the time, my statement referred to a dispute regarding the right choice of a baseline, and those examples I cited help to establish which baseline is more useful for most readers. Contrary to what you appear to have seen in the talk section I cited, I don't think that article is going to result in "our readers freaking out too much" - to me, it seems more likely to bore them to sleep. InformationToKnowledge (talk) 07:21, 14 March 2024 (UTC)

Are you willing to try a different approach? Uwappa (talk) 22:48, 13 March 2024 (UTC)

That's why I suggested Wikipedia:Dispute resolution noticeboard. I don't think me working one on one with InformationToKnowledge is going to be useful. Bogazicili (talk) 22:58, 13 March 2024 (UTC)

I'll admit that if no-one else here decides to take up the responsibility to choose between versions by the wen, it'll likely have to go to DRN after that. InformationToKnowledge (talk) 07:12, 14 March 2024 (UTC)

It doesn't really work like that anyway. If another editor voiced their opinion, I'd certainly consider it and factor their opinion in, but I'd still take it further along dispute resolution if I really didn't like the text. Compromise and consensus is more preferable. Uwappa and EMsmile, do you want to join Wikipedia:Dispute resolution noticeboard discussion? Bogazicili (talk) 09:32, 14 March 2024 (UTC)

I wouldn't go to Wikipedia:Dispute resolution noticeboard as the discussion is purely about content and uninvolved people would have a really hard time to follow. I do like the suggestion by Uwappa that the two of you work together in a Sandbox, as I somehow can't really follow those strike out, bolding etc. way of showing what is different. Or perhaps you could add just one sentence to the live article, wait for reactions, then add the next sentence. (I think the problem originally was that User:I2K added so much new text in one go that it was too much at once for anyone to follow)

For me personally, I generally stay away from the main climate change article because due to its FA status there is usually very strong resistance to change anything (rightly or wrongly). The FA status can sometimes feel a bit stifling but I can also understand that those who were involved in getting to FA status are sick and tired if they have to revisit stuff again and again, especially when it's had a recent FA review. But I had the problem once before at sea which was a featured article and then it made it really hard to change anything. This is not the case here though, editors are more open to changes and updates.

So for me, I tend to put my brain power into the sub-articles, even though it's not quite as satisfying as their pageviews are lower.

Sorry that I am not being more helpful with regards to the actual content questions here. I am pondering if we should ping RCraig09, Efbrazil and Femke although I am sure they have this on their watchlist so perhaps they don't want to be pinged (?). EMsmile (talk) 10:30, 14 March 2024 (UTC)

No I'm not doing the sandbox thing with InformationToKnowledge. We've been talking about this since the beginning of February. Enough. Bogazicili (talk) 10:55, 14 March 2024 (UTC)

Thank you Bogazicili for the invitation, but sorry, I won't join you to dispute resolution.

New suggestion: Try to reach disagreement on 2 core sentences in a sandbox.

• What would InformationToKnowledge's two core sentences be?
• What would your two core sentences be?

Take those two versions to dispute resolution, so it does not get lost in details.

Success! Uwappa (talk) 11:55, 14 March 2024 (UTC)

I have already listed what I consider to be the main 7 points of disagreement, and basically none of them are about "core sentences". I don't see how this would be helpful. InformationToKnowledge (talk) 09:15, 15 March 2024 (UTC)

@Bogazicili @EMsmile I started the Dispute Resolution discussion here. Since it appears that the other editors on this page are not particularly interested in this discussion (notice how many comments the most recent discussion about phrasing in the lead has attracted in comparison to this one), I opted not to include anyone else besides us three. InformationToKnowledge (talk) 09:24, 18 March 2024 (UTC)

Thank you. You may wish to renumber your current list: 1, 2, 3, 4, 4, 5, 5, 6, 7, 8. Please note 4th bullet of rules: "Ensure that you deliver a notice to each person you add to the case filing by leaving a notice on their user talk page." Success! Uwappa (talk) 10:43, 18 March 2024 (UTC)

Thanks for reminding me about this! Done. InformationToKnowledge (talk) 12:39, 18 March 2024 (UTC)

The sentence about 250,000 additional deaths

I've started a sub-heading here so that it's easier to follow. Regarding "I would say that for the first paragraph, both of us already agree that the WHO "250,000 extra deaths" figure is the core summary", I actually think this figure is not something that needs to be pushed and included, let alone be our "main message". I would exclude it from the climate change main article. It can be discussed in the sub-article on CC and health. I've already argued along the same lines last year; the discussion is visible in the archive here. I think the discussion didn't properly conclude and needs to be revisited (if you agree, shall I copy the discussion text across to here?). Basically, a figure of 250,000 extra deaths is rather meaningless, as all the indirect causes of death are not included. But more importantly, it puts too much emphasis on deaths whereas the more important issue with CC and health is the morbidity issue. We are not necessarily going to die from CC but life will be less comfortable and people will get more sick and suffer etc. EMsmile (talk) 10:19, 14 March 2024 (UTC)

It's just a number for estimates for several selected causes, nothing comprehensive: "The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to increases in diarrhea, malaria, dengue, coastal flooding, childhood malnutrition, and heat exposure in elderly people" Also, it's in the source this is not comprehensive, but I'm open to expanding it to say it's not comprehensive in the text too. Bogazicili (talk) 11:05, 14 March 2024 (UTC)

And the number is 10 years old by now (the WHO publication is from 2014). If there has been no updated figure on that in any of the literature in the last 10 years, not in the relevant Lancet "countdown" publications nor anywhere else, doesn't this tell us something? It's simply not relevant / reliable / up to date and therefore should not be included in this high level article. It can be in effects of climate change on human health and be spelled out in more detail there. EMsmile (talk) 13:16, 14 March 2024 (UTC)

It's also cited in IPCC AR6 WG2 (2022) as people pointed out in the archived topic you provided. We can also replace it with "Over 9 million climate-related deaths per year are projected by the end of the century" that you pointed out. Bogazicili (talk) 14:58, 15 March 2024 (UTC)

I agree that this can be left out, as it's quite outdated by now. Are the 9 million death climate or climate-change related? In the first case, it may be confusing to the reader. —Femke 🐦 (talk) 20:41, 18 March 2024 (UTC)

Here's the quote: "TS.C.6 Climate change will increase the number of deaths and the global burden of non-communicable and infectious diseases (high confidence). Over nine million climate-related deaths per year are projected by the end of the century, under a high emissions scenario and accounting for population growth, economic development and adaptation. Health risks will be differentiated by gender, age, income, social status and region (high confidence)." [IPCC AR6 WG2 Technical Summary p. 63] Bogazicili (talk) 20:48, 18 March 2024 (UTC)

So the IPCC is quite vague too, but seems to refer to CC-related deaths. Their referral to other sections that expand on this is terrible. I would like to know what they consider a high-emissions scenario (SSP6 or SSP8.5), given that the latter is very much a "very high emissions" scenario, which isn't too realistic anymore. Happy to highlight SSP6.0 though. —Femke 🐦 (talk) 20:55, 18 March 2024 (UTC)

I'm not wedded to a specific number, but I would strongly prefer the "Food and health" section mentions potential loss of human life in one form or another. WHO's number is more immediate (2030 and 2050) and narrow Bogazicili (talk) 21:03, 18 March 2024 (UTC)

Latest suggestions

• Here's Bogazicili's suggestion from above, just updated the formatting:

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[43] Extreme weather events affect public health.[44][45] Temperature extremes lead to increased illness and death.[46][47] Climate change can affect transmission of infectious diseases.[48] [49] The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to increases in diarrhea, malaria, dengue, coastal flooding, childhood malnutrition, and heat exposure in elderly people.[50] By 2100, 50% to 75% of the global population may face climate conditions that are life-threatening due to combined effects of extreme heat and humidity,[51]p. 988 which currently affects 30% of the global population.[52]

Despite overall increase in agricultural productivity, climate change has reduced water and food security, and have curtailed agricultural productivity growth.p.9 Agricultural productivity was negatively affected in mid- and low-latitude areas, while various high latitude areas were positively affected. p.9 Fisheries have been negatively affected in multiple regions.p.9 By 2050, climate change may affect tens to hundreds of millions of people in terms of undernourishment and nutrition-related diseases;p.60 change in population at risk of hunger may be positive or negative depending on several climate change and socioeconomic scenarios.[53] Depending on climate change trajectories, there will be increasing risks to food and water availability, and human health beyond 2040.pp. 14-15.

Bogazicili (talk) 20:28, 18 March 2024 (UTC)

• InformationToKnowledge's suggestion, copied from above

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century. It has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to impacts such as increased levels of extreme heat, greater frequency of extreme weather and changes in disease transmission. Lethal infectious diseases such as dengue fever and malaria are more easily transmitted in a warmer climate.[231] 30% of the global population currently live in areas where extreme heat and humidity can be potentially lethal, (CB reference) particularly to children and the elderly.[233] By 2100, 50% to 75% of the global population would live in such areas.[235]

Agricultural and socioeconomic changes had been increasing global crop yields since the middle of the 20th century, [Our World in Data reference] but climate change has already slowed the rate of yield growth.[IPCC AR6 WG2 Summary for Policymakers p.9] Fisheries have been negatively affected in various regions.[IPCC AR6 WG2 Summary for Policymakers p.9] By 2050, the number of people suffering from undernourishment and the associated health conditions is likely to decrease by tens to hundreds of millions, but some combinations of severe climate change and low socioeconomic development may increase that number instead. (2021 meta-analysis) By 2050, global livestock headcounts could decline by 7-10% under higher warming, as less animal feed will be available.[IPCC AR6 WG2 p.748] Extreme weather events adversely affect both food and water security, and climate change increases their frequency.[IPCC AR6 WG2 Summary for Policymakers p.9][230] If the emissions remain high, food availability will likely decrease after 2050 due to diminishing fisheries and livestock counts, and due to more frequent and severe crop failures.[IPCC AR6 WG2 p.797]

• Here's the compromise text for the first paragraph by Bogazicili. The bolded parts are InformationToKnowledge's wording (with "particularly to children and the elderly" taken out)

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[54] Extreme weather events affect public health.[55][56] Temperature extremes lead to increased illness and death.[57][58] Climate change can affect transmission of infectious diseases.[59] [60] The WHO has estimated that between 2030 and 2050, climate change would cause around 250,000 additional deaths per year due to increases in diarrhea, malaria, dengue, coastal flooding, childhood malnutrition, and heat exposure in elderly people.[61] 30% of the global population currently live in areas where extreme heat and humidity can be potentially lethal.[62] By 2100, 50% to 75% of the global population would live in such areas.[63]

Bogazicili (talk) 20:35, 18 March 2024 (UTC)

Discussions

Lets be brief here and use this subsection for discussion of above (and latest) suggestions. We can update the text in suggestions. Bogazicili (talk) 20:28, 18 March 2024 (UTC)

I was hoping to place the suggested versions side-by-side myself, but to do it directly on the DRN page. Their word count limits have hindered that, so I thank you for doing that instead.

However, I still have mostly the same issues with your suggestions:

1) I still don't think that mentioning the WHO at the start of the paragraph, then writing three very general sentences, and then mentioning the WHO again in a very long sentence (around 40 words!) makes for good or approachable encyclopaedic writing. To be fair, my proposed second sentence is about the same length, but I think it can be more easily split in half than your proposal.

2) Again, I think that any mention of temperature extremes and increased illness/death should be grouped together with the 50%/75% of the population under extreme heat and humidity part, not separated from it by two unrelated sentences.

3) I find it interesting that you chose to effectively weaken the wording on infectious diseases to a mere "can affect". When the next sentence effectively asserts that deaths from malaria, dengue and diarrhea will increase, this looks outright inconsistent. (We should also almost certainly use the full name of dengue fever, and to specify infectious diarrhea, as there are other kinds.)

4) I see that you still don't like my "particularly to children and the elderly" wording. Well, I found the full text of the study cited by the IPCC (and that CB article) and it actually includes this sentence: "The consequences of exposure to deadly climatic conditions could be further aggravated by an ageing population (that is, a sector of the population highly vulnerable to heat) and increasing urbanization (that is, exacerbating heat-island effects)". However, if you want to mention risk to the elderly in the WHO sentence itself, then this could work if the rest of that sentence is good.

5) After reading the full text of that study, I would rather modify my two closing sentences to the following: 30% of the global population currently live in areas where extreme heat and humidity are already associated with excess deaths. By 2100, 50% to 75% of the global population would live in such areas.

I really like this wording because it makes it very clear what the original study's definition of "deadly" means, much better than "life-threatening" (current) or "potentially lethal" (previous suggestion). InformationToKnowledge (talk) 09:34, 19 March 2024 (UTC)

For when the dust has settled, Copernicus ESOTC 2023 report about Climate and Health in 2023:

https://climate.copernicus.eu/esotc/2023/extreme-weather-and-human-health

Uwappa (talk) 06:19, 22 April 2024 (UTC)

Not Balanced

This article is not balanced. It does not present althernative or dissenting viewpoints, and as such this article violates the founding principles of Wikipedia. Bknewyork (talk) 12:59, 23 April 2024 (UTC)

See WP:FALSEBALANCE --McSly (talk) 13:26, 23 April 2024 (UTC)

Geo

Negative impact that climate change has on economy 41.13.80.60 (talk) 10:08, 23 April 2024 (UTC)

Are you suggesting a change to this article? Also it would be great if you could improve Economic analysis of climate change and Effects of climate change#Economic impacts Chidgk1 (talk) 13:44, 26 April 2024 (UTC)

Climate change, historic weather cycles

Respectfully, I have learned the most truth about climate and the current climate change from Ben Davidson's https://www.youtube.com/@Suspicious0bservers/featured and Thunderbolts Project https://www.youtube.com/@ThunderboltsProject/playlists

They make the whole picture fit together better than average information sources. With Respect Eva Zdrava 46.248.93.31 (talk) 15:06, 21 April 2024 (UTC)

Great, feel free to update the article once you have peer reviewed sources. 61.68.211.170 (talk) 04:07, 30 April 2024 (UTC)

Is it true that "The current rise in global average temperature is more rapid than previous changes"?

I don't know that the claim we make in the lead is correct. The IPCC source used to back the statement is blurring the issue of CO2 rise and temperature rise. The claim we make in the lead is exclusive to temperature.

The article on Bølling–Allerød warming appears to contradict the warming claim. Specifically, it says that at the end of the last ice age there was 3 C of warming in arctic waters within a period of 90 years. While global temperature records that far back are of course not as accurate, we do appear to know certain things, such as Meltwater pulse 1A causing sea level rise of 50 mm per year, which is over 10 times the current rate.

I don't know that we have enough information to uphold the claim we are making here in the lead. Most prehistoric temperature records do not have a resolution sufficient to make comparisons to modern times, and as recently as the last ice age there appear to be conflicting claims. Efbrazil (talk) 00:08, 8 May 2024 (UTC)

A good point. We can't make the unqualified claim that Efbrazil discusses, which would encompass 4.5 billion years of the planet's history. I propose we simply delete the words, "is more rapid than previous changes, and". —RCraig09 (talk) 05:25, 8 May 2024 (UTC)

I agree. Those words are not needed at that point of the lead (i.e. in the third sentence of the lead). It could be discussed later in the main text, if it's not already there. Whether the temperature rise is faster than ever before is not the key issue that we need to convey at the start of the lead. EMsmile (talk) 07:23, 8 May 2024 (UTC)

Change it to something that we can claim?

• The current rise is most rapid since the start of temperature records in 1850?
• Humans have caused the global temperature to increase to the highest level in the last 2,000 years?
• The current rise in global average temperature is the most rapid in at least 11.500 years?

Uwappa (talk) 13:50, 8 May 2024 (UTC)

Claims around temperature like the ones you list above may be accurate, but by only going back a few thousand years we are inviting the critique that current climate change can be natural and is nothing unusual. In general, I think speed is the wrong thing to focus on. Feedback loops and events like supervolcanoes and asteroids can result in rapid change, and the blurriness of the geologic record makes it difficult to make claims around speed in the first place.

If we want an addition that's a separate discussion I think. My understanding is that what's unnatural and extreme about current climate change is the CO₂ levels driving it. Additionally, we will soon be heading into temperature ranges not seen for millions of years. We could try to craft something around those points, but the lead is already very long, so I think getting to consensus on an addition will be difficult.

I went ahead and simply deleted the claim for now, as I think we all agree it appears to be suspect at best, and likely just wrong. Efbrazil (talk) 15:30, 8 May 2024 (UTC)

"3 °C (in less than 90 years)" increase in Bølling–Allerød warming seems to be in Alaska. Parts of the world also have faster than global average warming. Are there any sources about global average increase in Bølling–Allerød warming?

Meanwhile the current statement is well-sourced.

IPCC SR15 Ch1 2018, p. 54:

Since 1970 the global average temperature has been rising at a rate of 1.7 °C per century, compared to a long-term decline over the past 7,000 years at a baseline rate of 0.01 °C per century (NOAA, 2016; Marcott et al., 2013). These global-level rates of human-driven change far exceed the rates of change driven by geophysical or biosphere forces that have altered the Earth System trajectory in the past (e.g., Summerhayes, 2015; Foster et al., 2017); even abrupt geophysical events do not approach current rates of human-driven change.

AR 6 WG1 SPM-9: puts it this way. Bolding is mine:

A.2 The scale of recent changes across the climate system as a whole and the present state of many aspects of the climate system are unprecedented over many centuries to many thousands of years.
{Cross-Chapter Box 2.1, 2.2, 2.3, 5.1} (Figure SPM.1)
A.2.1 In 2019, atmospheric CO2 concentrations were higher than at any time in at least 2 million years (high confidence), and concentrations of CH4 and N2O were higher than at any time in at least 800,000 years (very high confidence). Since 1750, increases in CO2 (47%) and CH4 (156%) concentrations far exceed, and increases in N2O (23%) are similar to, the natural multi-millennial changes between glacial and interglacial periods over at least the past 800,000 years (very high confidence).
{2.2, 5.1, TS.2.2}
A.2.2 Global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2000 years (high confidence). Temperatures during the most recent decade (2011–2020) exceed those of the most recent multi-century warm period, around 6500 years ago13 [0.2°C to 1°C relative to 1850–1900] (medium confidence). Prior to that, the next most recent warm period was about 125,000 years ago when the multi-century temperature [0.5°C to 1.5°C relative to 1850–1900] overlaps the observations of the most recent decade (medium confidence).
{Cross-Chapter Box 2.1, 2.3, Cross-Section Box TS.1} (Figure SPM.1)

I think abruptness and it being unprecedented over a very long time are important points that are worth mentioning in that part of the lead. That statement has also been there for a very long time, but we can do an RfC if you want to insist on a change. Bogazicili (talk) 18:36, 8 May 2024 (UTC)

I see the information has been removed from the body at some point, and that the sourcing in that part of the body has become weaker (like primary sources and news articles). I think it's an important statement, but that we may want to move it back into the body, and possibly remove it from the lead. I think it's true, but it may not be DUE for such a prominent position in the lead. —Femke 🐦 (talk) 18:51, 8 May 2024 (UTC)

Was it removed with an edit summary that talks about improving wording, readability, etc? Bogazicili (talk) 18:55, 8 May 2024 (UTC)

I have no clue when it was removed. I can see that Efbrazil has a high authorship of some of the new text, so they have possibly paid more attention to changes to that section and seen it being removed? —Femke 🐦 (talk) 18:57, 8 May 2024 (UTC)

I am also asking, because I also thought this edit summary was misleading [64]. It asks for a source, but the source and quote is already there? Am I misinterpreting this? Bogazicili (talk) 19:02, 8 May 2024 (UTC)

I was assuming this was simply an accidental error from writing too fast —Femke 🐦 (talk) 19:05, 8 May 2024 (UTC)

The sourcing provided for the lead text speaks only to CO₂ levels or changes since the last ice age ended. It does not correspond to the text itself, which says warming "is more rapid than previous changes", which is inclusive of not just the last ice age but arguably all time before then.

Femke cut the content on warming since the last ice age on the basis that it was recent information. In that case, the rate of warming since the last ice age is an unknown, correct? Further, there are warming events earlier in Earth's history that happened on completely unknown time scales.

No matter how you look at it, the statement in the lead is simply false. Femke, please provide sourcing for the content or cut it. Efbrazil (talk) 19:21, 8 May 2024 (UTC)

The source is the 2018 one bogazicili cited above. —Femke 🐦 (talk) 19:28, 8 May 2024 (UTC)

I see your point, the text has been amended to talk about temperature rise, rather than climate change. So the source no longer fully supports it. We could go back to old wording? —Femke 🐦 (talk) 19:30, 8 May 2024 (UTC)

Did someone "improve the wording" on that part of the lead too? Bogazicili (talk) 19:32, 8 May 2024 (UTC)

The text in the last reviewed version of the article (2021) said: "However, the modern observed rise in temperature and CO2 concentrations has been so rapid that even abrupt geophysical events that took place in Earth's history do not approach current rates". The and is doing a lot of work there, as it's much easier to show GHG emissions are unprecedented. Still, I would be okay restoring that sentence, cited to SR15, and remove the lead sentence. —Femke 🐦 (talk) 19:35, 8 May 2024 (UTC)

The lead from FAR: "Though there have been previous periods of climatic change, since the mid-20th century, humans have had unprecedented impact on Earth's climate system and caused change on a global scale" [65] Bogazicili (talk) 19:37, 8 May 2024 (UTC)

Most editors here seem to be missing the point that the unqualified language implies that there has never been a previous temperature change faster than the present. Because of interval gaps in the proxy record, science simply can't make that unqualified statement, even if we find a reference has language that seems to imply it. Specifically: I remember seeing roaring honking jaw-dropping big temperature changes when I was working on , and I had to smooth the readings. Surely we can temper our presentation of the speed of global warming while preserving its seriousness. —RCraig09 (talk) 19:58, 8 May 2024 (UTC)

@RCraig09: made a suggestion below with more qualified wording. Bogazicili (talk) 20:22, 8 May 2024 (UTC)

Femke, the IPCC is clearly scoping their statement on climate to the holocene, which is not at all what we are doing in the current text or the FAR text. Do you not see that? Efbrazil (talk) 23:27, 8 May 2024 (UTC)

The second citation of the IPCC SR15 compares the expected forcing this century with the last 420 million year, to say it's unprecedented. The cited book covers 450 million years. We can more easily trace forcing back that far, compared to temperatures.

It's not a leap for the IPCC to say temperature rise is therefore also unprecedented, as it directly follows from forcing. However, the reservations here are fair, and putting this statement in the lead when there are so many caveats is not great. I believe there is a rough consensus to remove this for now, with a possibility to add something back. I would still like to see something of this kind in the body of the article, but more accurate (i.e. talking about climate change rather than temperature rise). —Femke 🐦 (talk) 16:20, 9 May 2024 (UTC)

I believe two extremely important points are being missed here.

The article on Bølling–Allerød warming appears to contradict the warming claim. Specifically, it says that at the end of the last ice age there was 3 C of warming in arctic waters within a period of 90 years. - I thought you would know we should not cite our own articles - particularly not when they are C-level. Have you actually evaluated the claim? The reference cited does not appear to say anything of a kind, although half of it is paywalled.

Further, even if it can be verified, Arctic amplification is a very consistent phenomenon, and it is now 3-4 times faster than the global average - meaning that the Arctic would have already warmed by 3-4C. Granted, the claim is for water temperatures, and those tend to warm slower, but the complexities of current flows make extrapolation from Alaskan waters to global surface temperatures an even more dubious proposition anyway.

Thus, Bogazicili is completely right in asking Are there any sources about global average increase in Bølling–Allerød warming? I still cannot find an exact figure for now: what I did find, however, was an indication that the warming was limited to the Northern Hemisphere, while the Southern Hemisphere cooled. Figure c) on the lower-left appears to show this the best. There is also no other mention of a 90-year interval specifically: the closest might be in this reference: The results obtained with three methods shows at least three rapid and abrupt short-term events which punctuate the Late-glacial interstadial in the Alboran and Aegean Seas at 14.1−13.9, 13.5−13.4. and 13−12.6kyr BP, and may be related to the Older Dryas, Greenland Interstadial-1c2 (GI-1c2) and the Gerzensee Oscillation respectively You would need to look deeper into this to find out about the temperature change during those periods, and if it there is evidence beyond the local scale. This reference does describe very rapid change in local ocean temperature, but again, neither that paper nor the associated literature go on to describe the rate and extent of global change.

The other point is much simpler: While global temperature records that far back are of course not as accurate, we do appear to know certain things, such as Meltwater pulse 1A causing sea level rise of 50 mm per year, which is over 10 times the current rate. - This does not tell us much of anything about the warming rate. Ice sheet retreat is determined by ice sheet structure and topology first, and temperature changes second. It is universally accepted that the Eurasian and Laurentide ice sheets which collapsed at the time were much less stable than the presently existing Greenland and Antarctica ice sheets. You cannot use the rate of their retreat relative to present as evidence for the rate of warming compared to present. InformationToKnowledge (talk) 19:57, 9 May 2024 (UTC)

For now, I restored the wording from the FAR version of the article into the body [66] Bogazicili (talk) 20:16, 9 May 2024 (UTC)

This seems like a good first step, thanks. However, I think this discussion had already revealed an important issue: that our Bølling–Allerød warming is clearly not fit for purpose. If a veteran contributor has been this misled by wording used in that article, what would the lay readers think?

I am quite busy with Climate change in Asia and the like at the moment, but these comments should provide enough references to fix the most egregious issues in that article: does anyone else want to try it? InformationToKnowledge (talk) 20:29, 9 May 2024 (UTC)

P.S.

As the world emerged from the last Glacial period, OMZs underwent a large volumetric increase at the beginning of the Bølling-Allerød (B/A), a northern-hemisphere wide warming event, 14.7 ka (Jaccard and Galbraith, 2012; Praetorius et al., 2015) with deleterious consequences for benthic ecosystems (e.g., Moffitt et al., 2015). - AR WG1, 715 InformationToKnowledge (talk) 20:18, 9 May 2024 (UTC)

@InformationToKnowledge: looks like Efbrazil also referred to another Wikipedia article when removing sourced material (specifically the restored FAR wording about warming in the body) back in 3 August 2023 [67]. What's your opinion about the article on Abrupt climate change and the removal in 2023? Bogazicili (talk) 15:42, 10 May 2024 (UTC)

@Bogazicili This is a bit more complicated. On one hand, abrupt climate change article is a mess I never seem to get around to doing anything about. It appears to regularly switch between the geologic definition of "abrupt" and the colloquial one, and many of its citations are either obsolete or seemingly used in a misleading manner. Sometimes, I am tempted to just merge it into tipping points in the climate system entirely, as it appears that in the modern context at least, the term "tipping point" has completely superceded "abrupt climate change". I.e. the 2008 U.S. Climate Change Science Program report on Abrupt Climate Change largely discusses the same things we now refer to as tipping points - the ice sheets, permafrost, AMOC, etc. Most of the "past examples" in that article are also associated with the same things as the modern tipping points, so they should not present an obstacle to merging.

With the passage Efbrazil is citing, it is technically correct that the research had found this much warming in Greenland and that it had occurred this quickly - unfortunately, it fails to clarify that the arctic amplification and land surfaces warming faster than the ocean (and therefore the planetary surface, which is 70% ocean) means that any global change would have been several times smaller.

Further, YD appears similar to Bølling–Allerød in that the consensus describes it as another thermohaline circulation event, where changes in the Norhern Hemisphere we are talking about have the opposite sign to those in the south: cooling in one hemisphere more-or-less balances warming in another. Thus, referring to it (even in an edit summary) in the same sentence which discusses the very global PETM is egregiously wrong. I have spent a lot of time cleaning up the AMOC article in the past couple of months (earlier, we didn't even have an accurate description of how its water masses connect to the global ocean, for starters), but it appears there is still a massive gap regarding its role in all of these Pleistocene events that needs to be filled.

On the other hand, I have to say that the reference provided in the revision before Efbrazil's is not ideal. It is primary research (which FAR apparently found acceptable, so maybe we could broaden food/health referencing as well?) and more importantly, it only mentions "temperature" once. It supports the rate of CO₂ increase well, and we can keep it for that (though I won't stop anyone from using a secondary one in its place) but I suggest we use the following for temperature:

New ocean heat content (OHC) reconstructions derived from paleo proxies (Bereiter et al., 2018; Baggenstos et al., 2019; Shackleton et al., 2019; Gebbie, 2021) indicate that the global ocean warmed by 2.57°C ± 0.24°C, at an average rate of about 0.3°C ka–1 (equivalent to an OHC change rate of 1.3 ZJ yr –1) from the LGM (about 20 ka) to the early Holocene (about 10 ka; Section 9.2.2.1 and Figure 9.9). Over the LDT, ocean warming occurred in two stages, offset by some heat loss during the Antarctic Cold Reversal (14.58–12.75 ka). Only during a short period of rapid warming at the end of the Younger Dryas (12.75–11.55 ka) were rates comparable to those observed since the 1970s - AR WG1, 349 InformationToKnowledge (talk) 19:52, 10 May 2024 (UTC)

@InformationToKnowledge: thanks for the detailed answer, it's good to keep this on record in the talk page. The original FAR version did not have that primary source, only the secondary source (IPCC SR15 Ch1 2018, p. 54) [68]. In the diff I provided, the secondary source is also there, you might have missed it given the long citation of primary source [69].

For the source you provided, the current wording mentions not only temperature but also C02 increase. What do you think of the current source and wording?

For food/health, we should first conclude the process ongoing since February I think. But overall, I agree that we should be specific and not open-ended (open-ended: things will be severe; specific: there could be x, y, and z happening). I have no intention of being "alarmist" or scaring people into not having kids due to climate change. Bogazicili (talk) 16:26, 12 May 2024 (UTC)

AR 6 WG1 SPM-9 has more conservative wording: "A.2 The scale of recent changes across the climate system as a whole and the present state of many aspects of the climate system are unprecedented over many centuries to many thousands of years." I'm thinking we can just put some of this and later parts from WG1 in quotes and replace the current sentence in the body:

Recent changes, such as increase in CO2 concentrations and global temperature, "are unprecedented over many centuries to many thousands of years." [AR 6 WG1 SPM-9] Including high emission scenarios, future projections of global temperature and CO2 increase are "similar to those only from many millions of years ago." [AR 6 WG1 Technical Summary p.44]

Bogazicili (talk) 17:11, 12 May 2024 (UTC)

Arbitrary break

Suggested change in text for the lead:

• Current:

  Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels.[3][4]

• January 21, 2021 Featured article review version:

  Though there have been previous periods of climatic change, since the mid-20th century, humans have had unprecedented impact on Earth's climate system and caused change on a global scale.[2]

• My suggestion:

  Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is caused by humans. Resulting changes on Earth's climate system are unprecedented in a long time.

No need for "is primarily caused by humans burning fossil fuels" in the current text since the next sentences in the lead already explain fossil fuels and greenhouse emissions parts. Bogazicili (talk) 20:25, 8 May 2024 (UTC)

Again, science can't claim "unprecedented" over 4.5 billion years; since it's hard to qualify, it can be omitted. On the other hand, the fact that humans cause global warming by burning fossil fuels, underlies the relevance of the ensuing sentences that describe the greenhouse effect, and that causation fact should be retained. —RCraig09 (talk) 20:34, 8 May 2024 (UTC)

That's why I suggested "unprecedented in a long time". Bogazicili (talk) 20:36, 8 May 2024 (UTC)

RCraig09, updated my suggestion. Bogazicili (talk) 22:00, 8 May 2024 (UTC)

Sorry, but "long time" is ambiguous—especially unsuitable for a science-related article. —RCraig09 (talk) 22:12, 8 May 2024 (UTC)

Refs

Click at right to show/hide refs
References

Wiki Education assignment: EEB 4611-Biogeochemical Processes-Spring 2024

This article was the subject of a Wiki Education Foundation-supported course assignment, between 16 January 2024 and 11 May 2024. Further details are available on the course page. Student editor(s): Floralepe (article contribs).

— Assignment last updated by LynSchwendy (talk) 03:29, 14 May 2024 (UTC)

This article is unlikely to be a suitable article for students to edit. It is in any case locked for newbie editors. I guess you could make suggestions for improvements here on the talk page. But my advice to students would be to rather work on any of the many sub-articles, like effects of climate change on the water cycle. EMsmile (talk) 17:51, 28 April 2024 (UTC)

Reference formatting

A lot of recent additions by Efbrazil use long in-line citations [70] [71], contrary to Talk:Climate_change/Citation_standards. Consistent citations are a Wikipedia:Featured article criteria. Is there any need for change for this? I think short ones work best for this article, given we cite sources like IPCC sources many times with different page numbers. And the majority of citations are already in that format. Bogazicili (talk) 20:32, 9 May 2024 (UTC)

My preference (and I suspect, that of many other editors) would be to convert the article to the in-line style we use elsewhere. I find that the short style makes it harder to access reference validity at a glance while editing in source (important even here, when much of the article is sourced to >10-year-old reports that ideally should be replaced with AR6 equivalents by now), and it requires more time to parse the reference list altogether - instead of immediately seeing the title, URL/DOI link, etc., you just see author name and date, and have to keep hovering over each reference to see those details. I suspect that if we were to eventually convert everything to in-line style, we would find that a lot of the references like 142; National Academies 2008, p. 6 could be safely cut in favour of AR6 page numbers and the like, but as long as this reference style stays, it'll remain in the same torpor.

Further, the short ref style seems to encourage "joint" references, like at 34, 95, 112, 368, 371, 391, 407 and perhaps more, when the same ref somehow cites two very different sources at the same time. I can sorta the logic when it's done with the "lay summary" parameter in the in-line template (though even then, I have passed GAs with three different reviewers and none told me to use that), but it's completely ridiculous when sources years or decades apart are somehow jumbled into one thing! I think that if this article is converted to in-line style, we would be able to standartize all of this. InformationToKnowledge (talk) 21:05, 9 May 2024 (UTC)

I think short in-line is far better for a contentious topic. The page numbers make it easier to locate and verify the information from a lengthy source, such as books or IPCC reports. Using the same source with different page numbers like this [330]:5 looks ugly and distracting. Imagine that format repeated so many throughout the article, like [330]:5, [118]:50-60 Long in-line only works for short journal articles or web pages, the type of shorter source where you don't really need page numbers to locate the information. Bogazicili (talk) 21:11, 9 May 2024 (UTC)

I find that "ugly and distracting" point is extremely subjective. I don't think it should outweigh the benefit of being immediately able to tell how many times a single reference is cited throughout the article, as opposed to...manually counting throughout the reference list, I guess? I have cited Climate change in Asia dozens of times to the corresponding AR6 chapter just recently, and I really don't think that style would have been an improvement there. InformationToKnowledge (talk) 21:18, 9 May 2024 (UTC)

Since we are discussing references, I would like to bring up another, perhaps even more important point: does this article actually need everything that's on top of the reference list? First lots of links to individual IPCC report chapters starting from AR4 (merely turning 17 this year) and AR5 (now decade-old), then a hundred or so of "Other peer-reviewed sources", most of them primary, then a few more dozen of "Books, reports and legal documents" and then a couple more dozen of "Non-technical sources".

How many people do we expect to read any of this? After they read this nearly 10k-word article, how much of this would even be necessary? If people need to see chapters from the (old) IPCC reports that we haven't already cited in-line, wouldn't they just go to the corresponding articles? And if we apparently shouldn't cite primary sources if there is an alternative, why is a whole collection of them, selected with minimum oversight and no immediately apparent reason for what makes them more important than the rest is acceptable? InformationToKnowledge (talk) 21:23, 9 May 2024 (UTC)

I honestly think it's a readability issue, with blue hyperlink and black page numbers, and the text is also black. This is a modified version from a village pump discussion:

Short and long mixed	Long only
The Sun is big. The Sun is really big. Don't look at sun with naked eyes. The sun is really big and this is coming from several big books. References . Sources Miller, Edward (2005). The Sun. Academic Press. xyz. (2022). The other book'	The Sun is big. The Sun is really big. Don't look at sun with naked eyes. The sun is really big and this is coming from several big books. References

You can tell how many times a source is used with Ctrl+F. For the above example, it'd work if you search for "Miller 2005" Bogazicili (talk) 21:32, 9 May 2024 (UTC)

Erm...maybe don't cite 20-30 pages at once? Those superscript "250–270" seem to be the main readability issue - on top of effectively defeating the whole point of using page numbers. I don't really see why we would ever need to cite pages in this way, and I don't think there any issue without that. InformationToKnowledge (talk) 21:54, 9 May 2024 (UTC)

That was just an example, it could be a single page too. How will you cite page numbers in long inline format then, when same source is used with different page numbers throughout the article? Like IPCC AR6 WG1. Or will you have a different named reference for each different page number groups? Bogazicili (talk) 22:00, 9 May 2024 (UTC)

I agree with I2K that the references section needs work and tidying up (and shortening). I also much prefer the long ref style, which is far easier to use for newcomers and for when text blocks are moved from one article to another. However, for this particular climate change article, I wouldn't even want to attempt to change it over to long ref style as there are so many references. It would take forever.

I think it's OK if Efbrazil has recently added some refs in long ref style. Many articles use a mixture of both styles (maybe not ideal in theory but seems to be happening). And I think those superscript numbers that indicate the page numbers are OK, not overly distracting and very useful. And being able to see with one glance if one ref is used dozens of times is also useful.

So in summary, my opinion is: I'd say leave this article as short ref style (but accept newer additions being added in long ref style) but make all the other smaller climate change sub-articles in long ref style.

By the way, a month ago I put this on the talk page but it was archived without a reaction: "I noticed that there are quite a few of these notifications in the list of sources now: "Harv warning: There is no link pointing to this citation. The anchor is named CITEREFThe_Guardian,_26_January2015." (I can't remember now if one needs to have a script installed to see this Harv warnings or if they're always there). Can someone, or shall I, remove those particular sources now? I assume they are "left overs" when sentences were removed." EMsmile (talk) 07:41, 10 May 2024 (UTC)

So you are saying someone else should fix the formatting when the times comes for the next Featured Article Review?

For sources no longer used, they should be removed. I believe there is a bot for that. Bogazicili (talk) 14:55, 10 May 2024 (UTC)

Historically, I've often tidied up after people, ensuring we still comply with the featured article criteria. It's my least favourite job on Wikipedia, and I really hope we can make it a group effort instead. Per WP:CITEVAR/WP:BIKESHED, it's generally good practice to not relitigate this over and over again. The long-form + rp format has accessibility and readability issues: It uses a small font, the meaning of the page numbers is not obvious to the non-initiated, and it causes more distraction away from the key text. A bit similar to why overcitation is a useability issue. EMSmile, feel free to cull sources that are no longer used, there is no need to ask for permission for such housekeeping. —Femke 🐦 (talk) 15:38, 10 May 2024 (UTC)

The ideal user experience is to click a number next to a statement you want to learn more about, see the full reference including page numbers, then click that link to go straight into the reference material. Too many of our links in this article require clicking several times inside the references section and ending at a place with multiple links. For instance, take our very first reference in the article, which is [3]. You get this:

IPCC SR15 Ch1 2018, p. 54: These global-level rates of human-driven change far exceed the rates of change driven by geophysical or biosphere forces that have altered the Earth System trajectory in the past (e.g., Summerhayes, 2015; Foster et al., 2017); even abrupt geophysical events do not approach current rates of human-driven change.

Which links to this:

IPCC (2018). Masson-Delmotte, V.; Zhai, P.; Pörtner, H.-O.; Roberts, D.; et al. (eds.). Global Warming of 1.5 °C. An IPCC Special Report on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty (PDF). Intergovernmental Panel on Climate Change. Global Warming of 1.5 °C –.

Allen, M. R.; Dube, O. P.; Solecki, W.; Aragón-Durand, F.; et al. (2018). "Chapter 1: Framing and Context" (PDF). IPCC SR15 2018. pp. 49–91.

Which contains 6 separate links, and two links in the specific target location. It's confusing. I'll try to follow the conventions, but I personally prefer inline references as a rule. They are easier to edit and are the standard on wikipedia in general. Bots fix things like dropped named references and typos are highlighted where they occur. Efbrazil (talk) 19:24, 14 May 2024 (UTC)

I agree with you Efbrazil; there is an extra click involved which is not necessary. (but I also see Femke's point that we cannot discuss this over and over again). However, do folks agree that when a new ref needs to be added then it's OK that it's added in long ref style (like Efbrazil has done) or are you strictly against that practice?

Also I wonder if we like or dislike the practice of adding a long quote into the ref, like it currently is for refs 6 and 7. I would be against it because it makes the ref list longer and it's not necessary. Isn't it also a potential for copyright vio (I notice those quotes are not always put in quotation marks; surely they would always have to be with quotation marks?)?

With regards to the unused sources, I am happy to report that the 12 unused sources have in the meantime already been removed in this edit by User:Tpbradbury on 17 April - thank you Tpbradbury. EMsmile (talk) 08:58, 15 May 2024 (UTC)

Proposed change to the lead paragraph

I'm thinking the lead should probably make clear what is unusual about current warming. CO₂ levels seem to be the most obvious issue. In the article we say CO₂ levels are higher than they have been for 2 million years, so I'm thinking we could bring that fact to the lead, like this:

In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices add to greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming.. These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary greenhouse gas driving global warming, has reached levels that are higher than they have been for millions of years. Efbrazil (talk) 16:52, 17 May 2024 (UTC)

• Agree in concept, but changing final sentence. To place in human-causation context, however, I would recite:

"In less than 200 years, carbon dioxide, the primary greenhouse gas driving global warming, has [ ] grown about 50%—to levels [ ] not seen for millions of years."

... or similar. Minor wording changes are welcome. —RCraig09 (talk) 20:17, 17 May 2024 (UTC)

• I like that 50% change. I would rather change the wording of some other sentences.

The current rise - why not "The current increase"?

is primarily caused by humans burning fossil fuels. Fossil fuel use, - any way to avoid this duplication? Perhaps "is primarily caused by greenhouse gas emissions from the consumption of fossil fuels. Deforestation, animal agriculture and certain other agricultural and industrial practices also emit greenhouse gases. These gases absorb..."

some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. We use warms/warming almost directly after each other. Perhaps use "heating" instead of warming, or some other synonymous word? Further, only a small fraction of warming goes into the lower atmosphere. Can we instead use "heating the ocean and the lower atmosphere"? (A reference to melting ice, which accounts for slightly more heat than the atmosphere, would be nice too, but is probably too difficult to fit in.) InformationToKnowledge (talk) 14:40, 18 May 2024 (UTC)

ITK: Not opposing your additional suggestions, but to avoid discussion bloat/digressions, it might be best if we focused/limited this particular section to discussing the final two sentences proposed by Efbrazil. PS — The "duplication" was discussed at length a few months ago: burning and use aren't duplication. —RCraig09 (talk) 17:19, 18 May 2024 (UTC)

I like RCraig09's suggestion. Time scale is important. The tense in the first sentence should be "have been warming the lower atmosphere" since this is an ongoing issue for some time. Bogazicili (talk) 17:20, 18 May 2024 (UTC)

The first sentence describes how greenhouse gases work, so the tense is correct I think.

The 50% increase is good, but the sentence is getting over long. I think to get it a little under control we can cut the 200 year part. That time frame is implied by the fact that we are pointing to the burning of fossil fuels earlier in the paragraph. Also, the vast majority of growth has just been in the last 60 years, so I think saying 200 years makes it sound even more spread out than it is.

Also, I'm not sure that the em dash is necessary. I think it's more accessible if we simply say "and" in place of that. So that would leave this:

These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary greenhouse gas driving global warming, has grown by about 50% and is at levels unseen for millions of years.

Thoughts? Efbrazil (talk) 23:37, 18 May 2024 (UTC)

Again, I would like to mention the ocean somewhere alongside "the lower atmosphere". It's a very important point.

I think to get it a little under control we can cut the 200 year part. That time frame is implied by the fact that we are pointing to the burning of fossil fuels earlier in the paragraph. I think that if you want to do that, we should expand one of the preceding sentences a little to clarify the timescale.

I.e. The current rise in global average temperature is primarily caused by humans burning fossil fuels. -> The current increase in global average temperature is primarily caused by humans burning fossil fuels since the Industrial Revolution. InformationToKnowledge (talk) 01:09, 19 May 2024 (UTC)

Yup, agree with that. Bogazicili (talk) 18:36, 19 May 2024 (UTC)

I also agree with ITK's 01:09 improvement over my 20:17 proposal, mentioning the time frame but introducing it earlier in the paragraph. —RCraig09 (talk) 00:15, 20 May 2024 (UTC)

Thanks all / done! Efbrazil (talk) 17:40, 20 May 2024 (UTC)

Proposed change to "Livelihoods and inequality" subsection: new section or paragraph explicitly on economy/labor/occupational safety and health

We must add the new information coming out from the International Labour Organization regarding the effect of climate change on labor, occupational safety and health, and the economy. Since I am a new editor to the page I wanted to give the courtesy of sharing that information first before jumping into any edits.

A report by the United Nations International Labour Organization released in April 2024 found that 22.85 million injuries and 18,970 fatalities in the workplace every year are linked to extreme heat exposure. [Source: Report found in PDF format on the webpage. Should consider archiving on web archive so that the text and pdf remain stable.]

By 2030, there will be an estimated 2.4 trillion USD financial loss due to heat-related illness, even if we limit the rate of warming to 1.5°C above pre-industrial levels. Furthermore, by 2030, 80 million jobs will be lost due to high temperatures. [Source]

I believe these facts merit at least their own paragraph because of the specific impact climate change will have on laborers' health in the workplace and therefore on the economy as a whole, as opposed to the broad-based health impacts on human health. Aem832 (talk) 15:34, 22 May 2024 (UTC)

Thanks for reaching out here. The issue is mentioned a couple times under the "Livelihoods and inequality" section. Feel free to edit but try to avoid projections and stick to core facts grounded in consensus science. For instance, a core fact is how many working hours will be lost per year due to heat stress. The extrapolations from that are best to avoid, such as job losses or heat stress deaths caused by people working when it is too hot to safely do so. You could easily argue for instance that work will instead become more limited and productivity will be lost so there will be more workers required. Focus on the core driving factor, not extrapolations from that fact. Extrapolations are often conjecture grounded in advocacy and imagine a world where other factors are held steady, such as working hours and technology and crop locations and so forth. A good place to put that sort of content is under Economic analysis of climate change. Efbrazil (talk) 16:14, 22 May 2024 (UTC)