Talk:Climate change

RFC: Food and health section

Which of the following sections should be used in the Food and health section?

Robert McClenon (talk) 04:47, 17 April 2024 (UTC)

A.

Human health

The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[1] Over 100 scientists writing in The Lancet have warned about the irreversible harms it poses.[2] According to the World Economic Forum, the most likely future scenario is of 14.5 million deaths caused by climate change by 2050.[3] Of those, 8.5 million deaths are associated with flooding, mostly because flooded areas expand the range of malaria. By 2050, the range of vector-borne diseases may expand to reach 500 million more people. Saltwater intrusion caused by sea level rise will also add over 800,000 cases of hypertension in coastal areas.[4]

Under the same scenario, around 1.6 million people will die in heatwaves by 2050, primarily those aged 65 and older, and 300,000 more will be killed by wildfires.[5] 30% of the global population currently live in areas where extreme heat and humidity are already associated with excess deaths.[6] By 2100, 50% to 75% of the global population would live in such areas.[7]p. 988 These and other climate change impacts are also expected to substantially increase the burden of stress-related mental health conditions.[8] The overall healthcare costs from climate change impacts would exceed 1$ trillion by 2050.[9] If the emissions continue to increase for the rest of century, then over 9 million climate-related deaths would occur annually by 2100.p.63

Food supply

Climate change has strong impacts on agriculture in the low latitudes, where it threatens both staple crops and important cash crops like cocoa and coffee.p.788 Agriculture will experience yield gains at high latitudes, but will also become more vulnerable to pests and pathogens.p.794 Extreme weather events adversely affect both food and water security, and climate change increases their frequency.p.9 Food prices spike after climate shocks.p.794 An increase in drought in certain regions could cause 3.2 million deaths from malnutrition by 2050, primarily in children under five. Many more children would grow up stunted as the result.[10] Under higher warming, global livestock headcounts could decline by 7-10% by 2050, as less animal feed will be available.p.748 Marine animal biomass decreases by 5% with every degree of warming, reducing fishery yields.p.718

In isolation, climate change is expected to increase the risk of hunger for 8 to 80 million people by 2050.p.725 However, total crop yields have been increasing since the middle of the 20th century due to agricultural improvements, and in spite of climate change.[11]p.832 By 2050, the overall number of people suffering from undernourishment and the associated health conditions is likely to decrease by tens to hundreds of millions.[12] Food security only worsens by 2050 in some combinations of severe climate change and low socioeconomic development,[13] but if the emissions remain high, it will likely decrease after 2050. This would be due to diminishing fisheries and livestock counts, and due to more frequent and severe crop failures.p.797

B.

The World Health Organization calls climate change the greatest threat to global health in the 21st century.[14] Over 100 scientists writing in The Lancet have warned about the irreversible harms it poses.[15] Extreme weather events affect public health, and food and water security.[16][17]p. 9 Temperature extremes lead to increased illness and death.[18][19] Climate change increases the intensity and frequency of extreme weather events.[20]p.9 It can affect transmission of infectious diseases.[21] [22] According to the World Economic Forum, 14.5 million more deaths are expected due to climate change by 2050.[23] 30% of the global population currently live in areas where extreme heat and humidity are already associated with excess deaths.[24] By 2100, 50% to 75% of the global population would live in such areas.[25]p. 988

While total crop yields have been increasing in the past 50 years due to agricultural improvements, climate change has already slowed the rate of yield growth.p. 9 Fisheries have been negatively affected in multiple regions.p. 9 Agricultural productivity was negatively affected in mid- and low-latitude areas, while some high latitude areas were positively affected. p.9 An increase in drought in certain regions could cause 3.2 million deaths from malnutrition by 2050 and stunting in children.[26] With 2C warming, global livestock headcounts could decline by 7-10% by 2050, as less animal feed will be available.p.748 If the emissions continue to increase for the rest of century, then over 9 million climate-related deaths would occur annually by 2100.p.63

C. Something else - Please provide a complete section.

Please enter A, B, or C (with the text) in the Survey. Please do not respond to the statements of other editors in the Survey.

Survey

• C1, When the dust has settled on text content, convert the agreed prose to a scannable layout, decrease word count, restructure text to chronology of current, 2050 and 2100. Example based on a merge of A and B:

Climate change is the greatest threat to global health in the 21st century.[27].[28][29][30]p. 9 [31][32] Climate change increases the intensity and frequency of extreme weather events[33]p.9 leading to increased illness and death.[34] [35]

Currently

• 30% of the global population live in extreme heat and humidity associated with excess deaths.[36]
• Food prices spike after climate shocks.p.794
• Climate change has slowed the rate of yield growth.p. 9[37]p.832p.9p.788
• Fisheries have been negatively affected in multiple regions.p. 9

2050, The most likely scenario

• 14.5 million deaths [38] by flooding and malaria [39], malnutrition by droughts, heatwaves, wildfires.[40]
• risk of hunger for 8 to 80 million people.p.725 Many children grow up stunted.[41]p.797[42]
• Agriculture yield gains at high latitudes, but more vulnerable to pests and pathogens.p.794
• With 2C warming, global livestock headcounts declines by 7-10%, as less animal feed will be available.p.748
• Marine animal biomass decreases by 5% with every degree of warming, reducing fishery yields.p.718

2100, The most likely scenario

• over 9 million climate-related deaths annually.p.63
• 50% to 75% of the global population would live in extreme heat and humidity.[43]p. 988
• substantial increase of stress-related mental health conditions.[44]

Uwappa (talk) 09:03, 19 April 2024 (UTC)

• I support option A because I think it makes sense to split it into two sections: one for health and one for food security. I have not dug deeper into which option uses the better references or numbers but Option A seems good to me. EMsmile (talk) 10:18, 19 April 2024 (UTC)

• Edit: None of the above Regarding A, the article is already over long, and particularly the section on impacts on humans relative to nature. We should be aiming to have less text in this area, not more. I am strongly opposed to A for this reason. B is generally alarmist rather than informative, and I get into specifics in a discussion with I2K down below. In my opinion the existing wording is better than either A or B. To progress, I think incremental changes would work best, targeting specific complaints with the existing text.Efbrazil (talk) 16:40, 19 April 2024 (UTC)
• Both A and B are very well written. Kudos to everyone who's worked on this. I prefer option B as it is more succinct and easier to understand. The shorter we make a given section, the more people will read it. Option C is not bad, but MOS:USEPROSE discourages this style for good reasons. Option B feels easier to read than C for me. Clayoquot (talk | contribs) 20:07, 19 April 2024 (UTC)
• Shorter B Kudos too to the editors and please make it shorter still Tom94022 (talk) 20:12, 19 April 2024 (UTC)
• Preferring B as more concise while keeping the gist. However, A's division of the material into two subjects has its merits. I object to the C approach given above, on two grounds: we should not "listify" content that can be presented as normal prose, per MOS:USEPROSE (WP is not a Powerpoint presentation); and WP is not in a position per WP:NOT#CRYSTALBALL to be trying to make predictions about the future and assign probabilities to them. To the extent any RS do the latter, these are particular researcher's opinions, and have to be attributed, and given WP:DUEWEIGHT.  — SMcCandlish ☏ ¢ 😼  00:44, 20 April 2024 (UTC)
• I prefer shorter one, which is B. Article is already overloaded with information. It would actually make a sense to create separate sub-articles if we want to elaborate more on some points. A b r v a g l ^(PingMe) 14:40, 23 April 2024 (UTC)

• C2, shorter scannable version of B, with current, 2050 and 2100

Climate change is the greatest threat to global health in the 21st century.[45], posing irreversible harms.[46] Climate change increases the intensity and frequency of extreme weather events[47]p.9, affecting public health, and food and water security.[48][49]p. 9 [50] [51] Temperature extremes lead to increased illness and death.[52][53]

Currently

30% of the global population live in areas where extreme heat and humidity are already associated with excess deaths.[54] While total crop yields have been increasing in the past 50 years due to agricultural improvements, climate change has already slowed the rate of yield growth.p. 9p.9 Fisheries have been negatively affected in multiple regions.p. 9

By 2050

14.5 million more deaths are expected.[55]. With 2C warming, global livestock headcounts could decline by 7-10%, as less animal feed will be available.p.748 An increase in drought in certain regions could cause 3.2 million deaths from malnutrition and stunting in children.[56]

By 2100

50% to 75% of the global population would live in extreme heat.[57]p. 988 If the emissions continue to increase for the rest of century, then over 9 million climate-related deaths would occur annually.p.63

Uwappa (talk) 12:03, 29 April 2024 (UTC)

Discussion

@Efbrazil: I understand your (and others') objections to option A based on length, but remember this discussion from the start of February, when many of us were looking to cut material from the "Causes" section, and you had yourself proposed removing 4-5 paragraphs? This option is still very much available: we simply couldn't do it at the time because Causes of climate change wasn't a live article yet, but it is done now. In fact, it often intentionally duplicates the current article, precisely to make it easier to cut from here. Thus, if we do in fact remove 4-5 paragraphs from causes but add 2 paragraphs here, on food and health, we will still ultimately have a shorter article.

I also think that every sentence in A provides unique and distinct information our readers would likely not know otherwise, but then again, I would think that as its author. I realize that all the editors who have so far voted for B may still want the section to be shorter rather than longer even after we condense "Causes". If so, which parts of A would you consider to be the most "skippable"? InformationToKnowledge (talk) 17:25, 22 April 2024 (UTC)

Thanks for reaching out. If we want to cut back the causes section that's fine, but I see that as a separate issue. It's not like the overall article has a word cap, it's more about relative weighting and preventing bloat. I don't feel strongly enough about cutting causes to try and push cuts there, but if you do then go for it. I agree that it is arguably too long as is.

Secondly, I don't see a need to grow this section in terms of relative weight, for a few reasons. I'm opposed to giving more weight to human impacts than we are giving to nature and wildlife. Humans are much more adaptable than much of nature and wildlife, and certain ecosystems that have taken millions of years to evolve may be extinguished. Further, a lot of the content regarding agriculture and health is highly speculative and suspect, verging into the mushy, advocacy based world of social "sciences". We can make solid predictions about the physics of climate change, but we can't say with any certainty how humanity will react and adapt. Efbrazil (talk) 17:49, 22 April 2024 (UTC)

I think it's quite hard to decide what the right weight is for different content. I am not in full agreement with your reasoning against expanding the content about effects of climate change on human health and food/agriculture. I don't think it's mushy nor advocacy based. What's mushy about the content at effects of climate change on agriculture?

But overall, there is probably no objective way to decide how much space to give to which content.

What I find a bit sad is that people who had to vote for A or B, seem to mostly just vote based on the word count of A and B: almost everyone seems to favor B because it's shorter. Probably the proposal A could also be made shorter if there was a word cap. I am assuming that the differences in the two versions go further than just their word count though?

Are people disagreeing that there should be two sub-headings: "human health" and "food supply"? I think those sub-headings make sense as they are distinct topics and it makes it easier to find them in the table of content in this way. Then again we do have a whole sub-article on effects of climate change so perhaps the whole section on "Impacts" here needs to have a rethink & re-focus.

And I think we should progress the discussion about condensing the "causes" section but I don't know how to go about it. We have a discussion thread above with 28 comments but it got stuck. Re-start it with a new section or someone rekindle it?

@User: Abrvagl We do have two sub-articles for these topics: (effects of climate change on human health and effects of climate change on agriculture). EMsmile (talk) 14:04, 24 April 2024 (UTC)

I've added the "section sizes" table to the top of the talk page so that it's easier to compare the length of sections. The Impacts section has 30 kB, the Causes section has 32 kB and the "Global temperature rise" section has 29 kB. "Impacts on humans" has 11 kB. EMsmile (talk) 14:16, 24 April 2024 (UTC)

Kudos for that, quite an interesting approach. I will take it on board. The thing is, that reader would rather prefer a small pre-read and a link to more details, which they can explore if interested, than an overloaded article, which reader has to scroll through to find a part they looking for. A b r v a g l ^(PingMe) 16:00, 24 April 2024 (UTC)

Typically a section is not just one paragraph. It is fine if we have one section that has two paragraphs, one focused on health and the other on agriculture.

The mushy, advocacy based stuff is when people make sweeping predictions about how many people will die or be malnurished or whatever. Not only is it hard to predict the timing and severity of climate change on a localized basis, we also have no idea how societies and technology will change in the future. Maybe we'll all be dead from bird flu, or AI will produce major advances, or there will be a new world war, or whatever else. Human systems are chaotic. If people could actually predict the future as it relates to society they'd be making a killing in the stock market. Let's stick to the climate and its environmental effects in this article. That's what we know. It is good that we mention health and agriculture, but there's only so much that can be said that isn't either conjecture or too vague to be useful. Efbrazil (talk) 17:35, 24 April 2024 (UTC)

@Efbrazil: If you consider IPCC or WHO or World Economic Forum, "mushy, advocacy based stuff", then we have a massive problem. Please review Wikipedia:Neutral point of view, WP:RS, and Wikipedia:What_Wikipedia_is_not#Wikipedia_is_not_a_soapbox_or_means_of_promotion. Bogazicili (talk) 18:40, 24 April 2024 (UTC)

EMsmile and Abrvagl, my goal with option B was to provide opening sentences/overall summaries (eg: "Extreme weather events affect public health, and food and water security") and giving several specific examples (ie: numbers). InformationToKnowledge's text (option A) is well-written and informative (and I actually used several sentences he wrote), but goes straight into details starting with the 3rd sentence, without giving overall summary/opening sentences. This is also seen in the page numbers of his sources (lots of 700's or 800's from IPCC report, rather than smaller page numbers from Summary for Policymakers or Technical Summary). This is too detailed. InformationToKnowledge had also argued about removing Effects of climate change on human health as an article (see Talk:Effects_of_climate_change_on_human_health#Article_appears_too_large_and_unwieldy_to_be_usable). I think sticking to WP:Summary here and keeping the main article (Effects of climate change on human health) is the better option. Bogazicili (talk) 18:59, 24 April 2024 (UTC)

Where did I dismiss the IPCC? All I said is we need to avoid conjecture. It is very easy to cherry pick statements or sources from a position of advocacy, and that is particularly true in the social sciences where there are innumerable possible outcomes. Anyhow, despite you having a massive problem with what I said and then dismissively saying I should educate myself on wikipedia policy, we generally agree on the substance here. Efbrazil (talk) 19:20, 24 April 2024 (UTC)

If that is your position, though, shouldn't you prefer the year 2050 projection for nutrition selected for A, which comes from a meta-analysis of dozens of papers, as opposed to the drought mortality figure from B, which is a fairly cherry-picked number unlikely to be representative of the overall trends in food supply/nutrition-related mortality? InformationToKnowledge (talk) 16:27, 26 April 2024 (UTC)

InformationToKnowledge had also argued about removing Effects of climate change on human health as an article I would like to clarify that my proposal was to merge that with the general Effects of climate change - following the logic that once we strip out the material from the article that appears to lack widespread support, such as the "people falling through thinner ice on frozen rivers" thing, there wouldn't be much left that would not be better covered in either that article, Climate change and infectious diseases or Psychological impact of climate change.

(I suppose should now say that we may end up being forced to remove a lot of material from that and many other sub-articles in the near future if WP:SCIRS ends up officially adopted in its stricter "cite no primary research findings whatsoever" form.)

I would like to further note that this recent WEF would seem to support this approach. Its title is almost the same as that of the article, about impacts on human health - yet, it is primarily focused on the health impacts from the various extreme weather events (Effects of climate change), mentioning that much of the mortality is from the associated increase in disease transmission (Climate change and infectious diseases) or on food supply (Effects of climate change on agriculture), and also notes the psychological impacts. There is effectively nothing there which does not fit into one of those sub-articles already. Chapter 7 in AR6 WG2 (Health, Wellbeing and the Changing Structure of Communities) does not appear to be very different. InformationToKnowledge (talk) 16:51, 26 April 2024 (UTC)

A bold alternative: Move away from what-when as it is impossible to predict the future. Go for what-if, climate change scenarios based on the limits from the Paris agreement.

• What is the current impact on environment, nature, wildlife, humans?
• What will be the impacts of + 1.5C?
• What will be the impacts of + 2.0C?

Show impacts in maps, similar to . Uwappa (talk) 08:39, 25 April 2024 (UTC)

That's been discussed before and would be a great thing to pursue, but would start in a lower profile article. Maybe a section in Effects of Climate Change, or even an entirely new article. Efbrazil (talk) 19:04, 25 April 2024 (UTC)

On the contrary, I don't think this would work well at all for this area in particular. Not only would the impacts of temperature thresholds be very different on the societal structures depending on the speed with which they will be reached, but specifically because any predictions of impacts on human populations are meaningless without an idea of the number, distribution, composition, etc. of those populations, and those are projected on a timeline, in accordance to certain scenario assumptions. InformationToKnowledge (talk) 16:24, 26 April 2024 (UTC)

@Efbrazil I'm opposed to giving more weight to human impacts than we are giving to nature and wildlife. Well, if that is your main objection, then once we remove 4-5 paragraphs from "Causes", that would leave us enough space to both have 4 paragraphs on food and health and to add 2-3 paragraphs to "Nature and wildlife". Considering the work I have done to date on articles such as Extinction risk from climate change or Effects of climate change on biomes (admittedly, more of a work in progress), it wouldn't be overly difficult for me to find reliably referenced material to complement the two paragraphs already present.

In addition, I would think we have some room to condense with the paragraphs which immediately follow "Food and health". Sentences like An expert elicitation concluded that the role of climate change in armed conflict has been small compared to factors such as socio-economic inequality and state capabilities. seem very awkward to say the least, and could be cut at least in part, if not fully. We have already argued over the limited reliability of this passage - In some regions, the rise in temperature and humidity may be too severe for humans to adapt to. With worst-case climate change, models project that almost one-third of humanity might live in Sahara-like uninhabitable and extremely hot climates. as well. There is most likely room to condense a paragraph or two there - and then the entire section devoted to impact on humans would be of similar size to "Nature and wildlife" once that is expanded by several paragraphs - likely even after "Food and health" is expanded to four paragraphs, and certainly if it stays at two.

Further, I noted this comment: B I could live with, but would want 4 sentences cut that are redundant with other areas or are just generally alarmist rather than informative. Would it be those four sentences, by any chance?

Extreme weather events affect public health, and food and water security.[92][93]p. 9 Temperature extremes lead to increased illness and death.[94][95] Climate change increases the intensity and frequency of extreme weather events.[96]p.9 It can affect transmission of infectious diseases.

Because a big reason why the DRN process was originally triggered was my opposition to those sentences, and Bogazicilli's insistence on keeping them. I can present my penultimate proposal before I opted for a four-paragraph structure (after amending it with the WEF data, that is), though I would rather not to. InformationToKnowledge (talk) 17:16, 26 April 2024 (UTC)

Yeah, "Causes" is a whopping 1942 words right now. "Impacts" is 1886, so nearly the same. Causes could be shrunk by a bit without any additions to impacts and I think it could be good. I suspect that if you wanted to incrementally try cutting back causes, going slowly and commenting well, that would be well received.

Yes, you understand what I mean about balance with the natural world. I'd certainly rather see another paragraph or two on the natural world before there's another paragraph or two on human impacts.

I spent some time rereading the proposals. On balance, I think the existing text on page is not bad. It does a good job of raising various issues without making dubious claims. Proposal A gets too far into the weeds for me and causes that word count imbalance with the natural world. Proposal B tilts too heavily towards generalized alarmism. As for cuts from version B, the 4 sentences you point to are generally fluffy and could be be folded into other sentences. The ones I was thinking of in specific are...

Over 100 scientists writing in The Lancet have warned about the irreversible harms it poses. --> This isn't even specific to human health or agriculture. Too vague and unnecessary, I think everyone at this point of the article is aware there will be irreversible harms.

An increase in drought in certain regions could cause 3.2 million deaths from malnutrition by 2050 and stunting in children. --> Almost all food scarcity is due to distribution issues, and "could" is wishy washy. Why not make a clear claim about agricultural output instead?

With 2C warming, global livestock headcounts could decline by 7-10% by 2050, as less animal feed will be available. --> Here we have something specific and probably valid, but not interesting given the context. We have a collection of sentences saying "millions will die!" followed by a sentence saying "we might lose a tiny fraction of our livestock capacity". Also, the IPCC report prominently mentions the need to consume less meat as part of conservation efforts. A 10% drop in livestock production would be a good thing for the climate and it's not going to cause problems like starvation and malnutrition.

If the emissions continue to increase for the rest of century, then over 9 million climate-related deaths would occur annually by 2100. --> Why focus on a scenario where emissions continue increasing for the rest of the century, particularly as we don't say how much even, and then attach a bs number to it? Nobody is predicting RCP 8.5 at this time.

In general, I feel like the best approach would be incremental fixes on the existing text, taken slowly. Efbrazil (talk) 22:37, 26 April 2024 (UTC)

Proposal A gets too far into the weeds for me and causes that word count imbalance with the natural world. Well, it's been said already that expanding the natural world in parallel would be one way to address the latter objection. As for the former, that's not really useful feedback. Can you at least identify the sentences you take an issue with, similar to what you have done for B?

On balance, I think the existing text on page is not bad. It does a good job of raising various issues without making dubious claims. -Not really. As we have discussed exhaustively on this page in February and March, several sentences are likely to be fairly misleading for a typical reader. I.e.

Climate change is affecting food security. It has caused reduction in global yields of maize, wheat, and soybeans between 1981 and 2010. - The straightforward read of that paragraph is that the current/2010 yields of those crops are lower than they were in the 1980s - and it would be completely wrong, because the comparison is drawn with the counterfactual present where climate change was not happening, while a clear increase had occurred in the real world.

Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts. - This sentence does not even specify anything. Up to 183 million by when? By next year? In 10 years' time? By 2050? (the correct answer). By 2100? Once climate change passes 2 degrees? Once it is at 6 degrees? Is it the maximum possible impact on hunger? This sentence is so vague that all these readings are equally valid. And again, this finding is relative to a counterfactual 2050, which is not very useful to general readers, which is why A has those two detailed sentences covering the actual projections relative to the present instead.

Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative. - I am surprised you don't seem to consider this sentence "wishy-washy" or too detailed.

Now, your comments about the proposed sentences.

As for cuts from version B, the 4 sentences you point to are generally fluffy and could be be folded into other sentences. I am glad you agree on this, but Bogazicili has been fairly insistent on those specific phrasings, leading up to the DRN.

This isn't even specific to human health or agriculture. Too vague and unnecessary - Well, this phrasing comes from the title, which is The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, and we both felt it was important to cite it here. I suppose we can rewrite this sentence with one or more findings from that report's summary graphic, but it might be best if you can specify which one you wouldn't oppose for one reason or another.

Almost all food scarcity is due to distribution issues, and "could" is wishy washy. Why not make a clear claim about agricultural output instead? - It is "could" to acknowledge that these projections are not set in stone (same point you were making earlier), and the number is for one scenario of several. However, A's final paragraph does discuss agricultural output. Would you prefer some variation of that wording?

Here we have something specific and probably valid, but not interesting given the context. Well, livestock is an important (even if technically skippable) part of the global food system, with a role comparable to fishing, so it makes no sense to mention one but not the other. Not to mention that an effective decimation is not tiny by any means. Literally the next sentence after that figure in the AR6 is: Changes to African grassland productivity will have substantial, negative impacts on the I cite this in Effects of climate change on livestock, but thought that it is "not global enough" for this section. However, I suppose it can be rephrased as With 2C warming, global livestock headcounts are likely to decline by 7-10% by 2050, affecting (can't think of a stronger word right now) the livelihoods of over 180 million people.

Why focus on a scenario where emissions continue increasing for the rest of the century, particularly as we don't say how much even, - I consider this a better phrasing than "high-emission scenario" or "worst-case climate change scenario" or the like. People could have vastly different ideas about what those mean, while this wording is immediately much clearer.

...and then attach a bs number to it? Nobody is predicting RCP 8.5 at this time. - So, you consider this alarmist? I actually view it the other way around. Too many people nowadays appear to believe that climate change would lead to billions dying, global collapse, etc. in the fairly near future. (See Climate change and civilizational collapse#Public opinion for the closest we have to objective evidence on the subject.) Thus, presenting this high-emission figure (again, from the AR6) as the "upper bound" for 2100 is actually likely to surprise a lot of people as "too low" - and those are the people who definitely need to see this, and are likely to scroll past the rest of the article and persist in their thinking otherwise. InformationToKnowledge (talk) 20:16, 27 April 2024 (UTC)

@Efbrazil So...I'll presume you have seen my reply above, even though you only chose to edit your previous comment a little about livestock and not reply to anything else. I'll again say that this 10% loss of livestock will be almost wholly concentrated in the developing nations such as Iran and much of Sub-Saharan Africa, which isn't exactly something to celebrate. And at least some of the benefit in terms of reduced emissions will be cancelled out as the more developed countries would respond by relying more and more on energy-hungry air conditioning and the like to preserve much of the other 90%, as already projected in multiple studies.

Even so, my point is that livestock is hugely important to a vast number of people around the world, many of whom will also be reading this article. If we want to be effective, we need to be able to speak to everyone - including to the people who care more about wallets than lives, and need to be told of the damage to their specific interests. InformationToKnowledge (talk) 20:07, 2 May 2024 (UTC)

I didn't reply because I think I made my points, and you made your points. The over riding message I tried to make is that I think you can make more progress working incrementally and slowly on page than you can by continuing this discussion and trying to find consensus behind a grand rewrite. Just start by editing a couple sentences that you think you can dramatically improve without adding to overall word count. Or start by making careful cuts from the causes section. If you work slowly then it lets people disagree with specific edits and they can back them out and open discussion on this talk page. I think you have a good sense at this point of what I will be opposing in terms of content. Efbrazil (talk) 20:50, 2 May 2024 (UTC)

I really wish we had more editors participating in this discussion. One would think that proposed changes to a fairly important section of an FA seen by over 3k people daily would attract more interest: particularly during a time of an RFC. Unfortunately, I am not sure if there is a way to go beyond what Robert McClenon had already done to attract feedback without breaching rules on canvassing and such. InformationToKnowledge (talk) 20:21, 27 April 2024 (UTC)

I do agree that the food and health section is fairly important. Yet don't expect to much of 3k daily readers. Look at "number of page watchers who visited in the last 30 days" instead, that stands at just 37 today. With only a handful of watchers actively participating in talks, it seems unrealistic to expect a big talking crowd here, especially after months of discussion. My recommendation: go for a shortened version of B, see C2 above and move on. Uwappa (talk) 12:23, 29 April 2024 (UTC)

@Uwappa At a glance, my main objection to that proposal is that it seems to portray the 3.2 million drought deaths figure as being additional to the 14.5 million figure, rather than part of the same estimate. So, we should either have only the combined figure, or another run-on sentence similar to the WHO one it'll be replacing (i.e. By 2050, 14.5 million deaths are likely, including 8.5 million from flooding and waterborne [water-associated?], 3.2 million from malnutrition due to droughts, 1.6 million from heatwaves by 2050 and 300,000 from wildfires. And again, I would not want to skip over the rather important situation where the bulk of projections say food supply would improve by 2050. InformationToKnowledge (talk) 19:57, 2 May 2024 (UTC)

After months of discussion, a DRN and a survey, it is unlikely that a new discussion will yield results.

Please stop. Uwappa (talk) 20:19, 2 May 2024 (UTC)

What new discussion? I objected to one sentence from your proposal, and expressed hope for adding another. Besides, even if I agreed to everything in that proposal now, that wouldn't have meant much unless the other active editors here all agreed as well, and so far, they are all silent. InformationToKnowledge (talk) 08:34, 3 May 2024 (UTC)

Uwappa, would you mind striking down your earlier comment in the survey section above with <s></s>? It looks like you voted twice now. Or make a comment that you made an alternate suggestion? Bogazicili (talk) 15:21, 3 May 2024 (UTC)

Done: C1 Uwappa (talk) 15:26, 3 May 2024 (UTC)

Thanks. I think for your proposal, there are too many short paragraphs per WP:PARAGRAPH. I also prefer attributions (" World Health Organization calls", "Over 100 scientists writing in", "According to the World Economic Forum"). This shows that a variety of sources have been used (medical professionals (WHO), scientists, business community (World Economic Forum) etc). Bogazicili (talk) 15:58, 3 May 2024 (UTC)

I doubt if the paragraphs really are too short. Each does present one idea: the expected situation in a year. Changed C2 from paragraphs to MOS:DEFLIST, definition list, which would be my own preference as a scannable layout gives 47% improvement according to Nielsen, 1997. Yes, I know, Nielsens result are now more than a quarter of a century old and many WP editors still prefer prose. Scannability is still an unknown concept in WP.

I do like the reliability of WHO and 'over 100 scientists', but... to decrease word count, what else to take out? Reliable sources can move to a reference. And they should be reliable as unreliable sources should never be used in the first place. Uwappa (talk) 17:09, 3 May 2024 (UTC)

I don't think there is any need to decrease the word count with Proposal B (my proposal). Its word count is 240 words. The current text in Food and health section has 243 words. Bogazicili (talk) 17:19, 3 May 2024 (UTC)

For the record, I am opposed to proposal B now, as per discussion up above with I2K. Several sentences are problematic and the existing wording is better I believe. In my opinion, the best approach is not a full rewrite but to make specific edits to the existing text where there is a belief that improvements are needed. Efbrazil (talk) 17:12, 4 May 2024 (UTC)

I would prefer the more concise B given we have {{main article}} links for readers seeking more detail. However, I find that B does not convey the same meaning as A, or even the existing wording: B currently states "Agricultural productivity was negatively affected in mid- and low-latitude areas, while some high latitude areas were positively affected". This gives the impression that agriculture in the high latitudes may only be positively affected, which does not contain the nuance that A has ("Agriculture will experience yield gains at high latitudes, but will also become more vulnerable to pests and pathogens"); the existing wording ("effects at northern latitudes may be positive or negative") shows this duality better (though "northern" should be reworded to "higher"). ~ KN2731 {talk · contribs} 11:55, 6 May 2024 (UTC)

@KN2731: B describes impacts until now in that sentence, whereas A describes future impacts. The page numbers in the sources are also different. B uses page numbers from summary pages (summary for policy makers or technical summary). The current wording also describes future impacts. Bogazicili (talk) 18:09, 6 May 2024 (UTC)

Thanks for pointing that out, I didn't notice that at first glance. I wonder if that sentence in B should be changed to present perfect tense ("has been negatively affected", "have been positively affected") to be consistent with the other sentences before it describing past to present impacts. ~ KN2731 {talk · contribs} 14:01, 11 May 2024 (UTC)

@KN2731: yes this can be done if and when B is implemented. For now, I'm not changing the text above, since people already voted. Bogazicili (talk) 16:28, 12 May 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)

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)

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)

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)

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 [58]. 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" [59] 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 [60] 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 [61]. 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) [62]. In the diff I provided, the secondary source is also there, you might have missed it given the long citation of primary source [63].

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

Reference formatting

A lot of recent additions by Efbrazil use long in-line citations [64] [65], 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)

Resolving the issue of rapid rates of change

At issue is two versions of events. There is FAR / Bogazicili text here, sourced to SR15 / page 54, which I just removed as being potentially inaccurate:

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.

Or there is this text talking about warming following the last ice age. I had added it a while ago in trying to describe the best research on the last ice age. Femke deleted it as recent research, which is fine by me, but I don't know of a more accurate (consensus) science on warming rates following the last ice age:

The warming that followed included a 500 year period when sea levels rose 18 meters (59 ft)

The reason I put the text in I did is that the meltwater pulse seemed like solid, global data. The Bolling-allerod warming article is important to read though. It includes this statement, which contradicts the claim made in SR15:

Records obtained from the Gulf of Alaska show abrupt sea-surface warming of about 3 °C (in less than 90 years), matching ice-core records that register this transition as occurring within decades.

Perhaps the SR15 statement is simply false now as it no longer reflects the latest science. My general view is that we simply should not make claims about how rapid climate change was prior to the anthropocene as the science isn't clear. I'm not saying we should say SR15 is incorrect, but I also don't want to blindly parrot SR15 when what it says is directly contradicted by our own ice age articles on wikipedia. Maybe the SR15 claim still works if it is isolated to CO₂ levels and not temperatures.

I'm hoping we can discuss the actual science here rather than wording or what was in FAR or this study or that study. Is there an expert that can say which claim (if any) is correct and why? Until we have consensus on what the science says, I think it is best that we avoid adding stuff to the article about it. I put an ask on the Bølling–Allerød wiki page for experts there to take part in this discussion. Efbrazil (talk) 17:41, 15 May 2024 (UTC)

Sorry, but it is my understanding that we should not discuss the actual science here. Wikipedia reports on reliable sources. We judge content by verifiability not scientific criteria of any kind. We can develop a consensus about content based on sources, but not based on science. Johnjbarton (talk) 18:00, 15 May 2024 (UTC)

AR6 is quite precise. Here's a modified version of my suggestion from above for the body of the article:

Recent changes, such as increase in CO2 concentrations and global temperature, "are unprecedented over many centuries to many thousands of years."AR6 WG1 SPM-9 Including high emission scenarios, future projections of global temperature and CO2 increase for the upcoming 300 years are "similar to those only from many millions of years ago." AR6 WG1 Technical Summary p.44

Bogazicili (talk) 18:18, 15 May 2024 (UTC)

RCraig09, any interest in replicating that graph in AR6 WG1 Technical Summary p.44? Bogazicili (talk) 18:27, 15 May 2024 (UTC)

@Bogazicili: I don't understand what you mean by "that graph". I think Figure TS.1 Changes in atmospheric CO2 and global surface temperature is far too detailed for an encyclopedia. —RCraig09 (talk) 20:23, 15 May 2024 (UTC)

Good, let's put aside the SR15 sentence then. Regarding the AR6 wording, the first sentence you offer seems to talk about the holocene (many centuries to many thousands of years), and that certainly seems defensible. However, I don't know that it is very compelling, as "many centuries" arguably only goes back to the middle ages.

The second sentence is more iffy as it is a projection going hundreds of years into the future and is exclusive to a high emission scenario that I believe is no longer being predicted any more than 1.5 degrees is. Ideally we talk 2.5 C to 3 C and look nearer term. As is it reads a bit like climate apocalypse writing, as in "if the worst happens and no new technologies come along then hundreds of years from now blah blah blah". Efbrazil (talk) 19:09, 15 May 2024 (UTC)

That is what the source says, but you seem to reject it based on personal opinions or personal interpretations. And no, it is not "exclusive to a high emission scenario". Bolding is mine:

For example, there is medium confidence that, by 2300, an intermediate scenario14 used in this Report leads to global surface temperatures of [2.3°C to 4.6°C] higher than 1850–1900, similar to the mid-Pliocene Warm Period [2.5°C to 4°C], about 3.2 million years ago, whereas the high CO2 emissions scenario SSP5-8.5 leads to temperatures of [6.6°C to 14.1°C] by 2300, which overlaps with the Early Eocene Climate Optimum [10°C to 18°C], about 50 million years ago.AR6 WG1 Technical Summary pp.43-44

Bogazicili (talk) 19:17, 15 May 2024 (UTC)

The first half of that AR6 statement you offered mostly repeats what we already have in the "future global temperatures" section. It could be added there, but should be reconciled with the existing statements, and we want to avoid article bloat. That's my personal reasoning at least :)

I think there are 2 larger issues. First, do we want to make any claims about rate of change? My reading from stuff right now is no.

Secondly, should the lead make a clear claim about what is unusual about current climate change? We could focus on CO₂ levels as we are clear on that. For instance, would you be in favor of changing 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.[3][4] Fossil fuel use, deforestation, and some agricultural and industrial practices add to greenhouse gases, notably carbon dioxide and methane.[5] GreenhouseThese 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 warmingCarbon dioxide levels are now higher than they have been for millions of years, causing Earth's lower atmosphere to heat up.

The basis is later in the article when we say CO₂ levels are higher than they have been for 2 million years. Efbrazil (talk) 20:59, 15 May 2024 (UTC)

@Efbrazil I'm sorry, but have you seen anything in my comment from last week? I know it was a long comment and I didn't ping you specifically, but I thought I didn't need to. Quick recap:

1. Bølling–Allerød warming only occurred in the Northern Hemisphere. This is literally the IPCC text: see AR WG1, 715. There are graphics showing how that warming was cancelled out globally by the Southern Hemisphere cooling. Unfortunately, it seems like absolutely nobody who wrote either the B-A article or the Late Glacial Interstadial one was ever aware of this point, so large numbers of people were in all likelihood misinformed by both.
2. Meltwater Pulse 1A cannot be used to draw conclusions about the rate of warming, because completely different ice sheets broke up from the present ones.

To be fair, the sentence from FAR is flawed - mainly because it just says "temperature" and not "global temperature", which means that you can conceivably challenge it with local events like Bølling–Allerød, and because its reference to "abrupt geophysical events" only muddies the waters - my impression is that outside of maybe the Siberian Traps volcanism (and the asteroid, if that counts) practically everything that gets described as an "abrupt event" is actually a continental or at most hemispheric-scale change like the B-A (which is one reason why the term appears to have been used interchangeable with "tipping point" for some time, before getting largely phased out in modern context - see my observations here, for instance), and so shouldn't be brought up in the discussion of global change in the first place.

New suggestion from Bogazicili seems to address this - although it can still be improved. Firstly, I would rather shorten Recent changes, such as increase in CO2 concentrations and global temperature,... in the first sentence to Recent increases in CO2 concentrations and global temperature... If we want to mention any other unprecedented change/increase in the lead, we should do it explicitly. Then, I don't know that it is very compelling, as "many centuries" arguably only goes back to the middle ages is certainly not how that statement was intended to be read, but I can see how this wording leaves open that possibility. So, I would like to bring up the following instead:

Over the last 50 years, global surface temperature has increased at an observed rate unprecedented in at least the last two thousand years (medium confidence), and it is more likely than not that no multi-centennial period after the Last Interglacial (roughly 125,000 years ago) was warmer globally than the most recent decade (Cross-Section Box TS.1, Figure 1). During the mid-Pliocene Warm Period, around 3.3–3.0 million years ago, global surface temperature was 2.5°C–4°C warmer, and during the Last Interglacial, it was 0.5°C–1.5°C warmer than 1850–1900 - AR6, WG1, TS, 28

And later, for CO₂:

The centennial rate of change of CO2 since 1850 has no precedent in at least the past 800,000 years (Figure TS.9), and the fastest rates of change over the last 56 million years were at least a factor of 4 lower - AR6, WG1, TS, 35

There is also CH₄, and we should really go there, too. After all, it's actually more certain than the other two metrics:

By 2019, concentrations of CH4 reached 1866.3 (± 3.3) ppb (Figure TS.9c). The increase since 1750 of 1137

29 ± 10 ppb (157.8%) far exceeds the range over multiple glacial-interglacial transitions of the past 800,000 years (high confidence).

I am not 100% sure on how to integrate this yet (presumably, we are only considering "Temperature records prior to global warming" and "Warming since the Industrial Revolution" right now, and not the lead or elsewhere?) I'll note that the paragraphs we use in those sections are fairly short, and trimming "Causes" would free up more space here too, but again, how to utilize it?

I guess that for now, my main suggestion would be here.

Over the last few million years human beings evolved in a climate that cycled through ice ages, with global average temperature ranging between 1 °C warmer and 5–6 °C colder than current levels. One of the hotter periods was the Last Interglacial between 115,000 and 130,000 years ago, when sea levels were 6 to 9 meters higher than today.

There is again that use of SLR as a stand-in for temperature, which is quite problematic. It would be nice to change this to something like

Over the last few million years human beings evolved in a climate that cycled through ice ages, with global average temperature ranging between 1 °C warmer and 5–6 °C colder than current levels. During the Last Interglacial between 115,000 and 130,000 years ago, temperatures were at most 0.5°C warmer than the current levels, yet sea levels were 6 to 9 meters higher than today.

The issue is that readers would undoubtedly see this as saying that reaching 1.5°C now would result in 6-9 m of SLR, and I don't know how to qualify it so that it's clear this would happen over thousands of years if it did. The wording on sea level rise - In the long run, sea level rise would amount to 2–3 m (7–10 ft) over the next 2000 years if warming amounts to 1.5 °C (2.7 °F). - is helpful (and also based on AR6), but how to add any of this into that section in a way that reads naturally? InformationToKnowledge (talk) 04:06, 16 May 2024 (UTC)

I'm fine with changes to the section on temperatures if you think it's necessary. You seem to be arguing with me but I don't know what about. We should probably base things on AR6 rather than SR15 though, as it is newer and seems more precise in its statements in this area.

Regarding Bølling–Allerød, the graphics don't support the "cancelled out" claim as far as I can tell. The IPCC text doesn't make that claim, and the maps you link to show overall warming (just driven by the northern hemisphere).

The larger point is that we only have annualized global temperature estimates going back 2000 years. Past that, the data is increasingly smeared over hundreds to thousands of years or is based on localized studies. That makes it difficult to make comparisons with global temperature changes over the past 50 years. Efbrazil (talk) 15:55, 16 May 2024 (UTC)