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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.
So, what are the other editors' opinions about this section? InformationToKnowledge ( talk) 22:39, 1 February 2024 (UTC)
Over 500,000 more adult deaths are projected yearly by 2050 due to reductions in food availability and quality.
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.
Climate change reduced the number of avoided deaths
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.
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.
Obviously, our hypothetical redistribution calculations cannot be interpreted in terms of expected migration.
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.
Under a high emission scenario, climate change is expected to place an extra 8 to 80 million people at risk of hunger by 2050.
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
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)
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)
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 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.
a third may stop being suitable for useto
a third may stop being usable by 2100, both specifying the date and making the wording less awkward.
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)
" 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)."
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.
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)
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.
"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.
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.
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.
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". [1]
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. [2]
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.
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 stressconveys a similar amount of information (more in fact, as it explains what caused the reductions), while avoiding all of the issues above.
Second paragraph does not accurately reflect the World Bank Source abovea) 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.
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:
InformationToKnowledge ( talk) 19:50, 5 February 2024 (UTC)
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
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] |
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)
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)
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.
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]
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) |
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 thisI 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.
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
Food availability would decrease globally by 3% under the climate stabilization scenario compared to reference levels by 2030.
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.
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.
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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)
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).
However, if you find another reliable secondary source, that can also be added.
The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[229]
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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!
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
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.
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.
while various high latitude areas were positively affectedis 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 regionsis 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.
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.
issues we haven't covered in this sectionthen...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.
@ 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)
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)
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]
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:
Once you agree on such a core, add more detail. Uwappa ( talk) 08:25, 13 March 2024 (UTC)
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]
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)
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)
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]
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)
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)
"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.
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.
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)
Negative impact that climate change has on economy 41.13.80.60 ( talk) 10:08, 23 April 2024 (UTC)
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)
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)
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.
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)
andis 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 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.
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 respectivelyYou 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.
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)
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)
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)
Bogazicili ( talk) 17:11, 12 May 2024 (UTC)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]
Suggested change in text for the lead:
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]
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]
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. [1] Resulting changes on Earth's climate system are unprecedented in a long time. [1]
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)
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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.
So, what are the other editors' opinions about this section? InformationToKnowledge ( talk) 22:39, 1 February 2024 (UTC)
Over 500,000 more adult deaths are projected yearly by 2050 due to reductions in food availability and quality.
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.
Climate change reduced the number of avoided deaths
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.
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.
Obviously, our hypothetical redistribution calculations cannot be interpreted in terms of expected migration.
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.
Under a high emission scenario, climate change is expected to place an extra 8 to 80 million people at risk of hunger by 2050.
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
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)
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)
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 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.
a third may stop being suitable for useto
a third may stop being usable by 2100, both specifying the date and making the wording less awkward.
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)
" 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)."
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.
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)
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.
"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.
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.
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.
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". [1]
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. [2]
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.
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 stressconveys a similar amount of information (more in fact, as it explains what caused the reductions), while avoiding all of the issues above.
Second paragraph does not accurately reflect the World Bank Source abovea) 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.
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:
InformationToKnowledge ( talk) 19:50, 5 February 2024 (UTC)
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
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] |
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)
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)
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.
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]
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) |
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 thisI 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.
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
Food availability would decrease globally by 3% under the climate stabilization scenario compared to reference levels by 2030.
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.
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.
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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)
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).
However, if you find another reliable secondary source, that can also be added.
The World Health Organization (WHO) calls climate change the greatest threat to global health in the 21st century.[229]
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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!
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
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.
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.
while various high latitude areas were positively affectedis 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 regionsis 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.
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.
issues we haven't covered in this sectionthen...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.
@ 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)
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)
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]
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:
Once you agree on such a core, add more detail. Uwappa ( talk) 08:25, 13 March 2024 (UTC)
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]
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)
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)
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]
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)
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)
"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.
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.
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)
Negative impact that climate change has on economy 41.13.80.60 ( talk) 10:08, 23 April 2024 (UTC)
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)
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)
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.
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)
andis 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 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.
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 respectivelyYou 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.
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)
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)
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)
Bogazicili ( talk) 17:11, 12 May 2024 (UTC)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]
Suggested change in text for the lead:
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]
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]
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. [1] Resulting changes on Earth's climate system are unprecedented in a long time. [1]
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)
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