Talk:Effects of climate change on agriculture

Structure needs further work

The structure needs a bit of further work as the first section is called "Impact of climate change on agriculture" which is basically the same as the title of the article.EMsmile (talk) 15:17, 7 March 2022 (UTC)

I've done some work on the structure but it's still not great. EMsmile (talk) 17:33, 10 March 2022 (UTC)

Should "Ozone and UV-B" and "UV radiation" sections be deleted?

Chidgk1 (talk) 17:58, 7 March 2022 (UTC)

Done. It was poorly sourced and outdated. EMsmile (talk) 10:21, 8 March 2022 (UTC)

Removed content about Evan Fraser research

I've removed this text block from the introduction because I felt it was overly detailed and didn't fit there. I am not sure if it fits elsewhere in the article?: But much remains unknown about exactly how climate change may affect farming and food security, in part because the role of farmer behaviour is poorly captured by crop-climate models. For instance, Evan Fraser, a geographer at the University of Guelph in Ontario Canada, has conducted a number of studies that show that the socio-economic context of farming may play a huge role in determining whether a drought has a major, or an insignificant impact on crop production. In some cases, it seems that even minor droughts have big impacts on food security (such as happened in Ethiopia in the early 1980s where a minor drought triggered a massive famine), versus cases where even relatively large weather-related problems were adapted to without much hardship. Evan Fraser combines socio-economic models along with climatic models to identify "vulnerability hotspots" One such study has identified US maize (corn) production as particularly vulnerable to climate change because it is expected to be exposed to worse droughts, but it does not have the socio-economic conditions that suggest farmers will adapt to these changing conditions. Other studies rely instead on projections of key agro-meteorological or agro-climate indices, such as growing season length, plant heat stress, or start of field operations, identified by land management stakeholders and that provide useful information on mechanisms driving climate change impact on agriculture. EMsmile (talk) 17:11, 10 March 2022 (UTC)

References

Split off the potatoe and wine part into sub-articles again?

It's not clear to me why you Chidgk1 merged the potatoe and wine articles into this article? I would be tempted to move them back into their sub-articles (but leave a short description, perhaps an excerpt). The article is now already very large (about 70 kB readable prose) and it's unclear why potatoes and wine should be given such a big amount of space (is it Euro-centric to pick potatoes and wine? If anything, shouldn't rice and maize be discussed more?). EMsmile (talk) 17:39, 10 March 2022 (UTC)

My preference would be for someone to shorten them by summarising (second pref might be to split off and excerpt lead back in) but I don't have a strong opinion and am not likely to work on this article, so up to you guys. Don't know how active Wikipedia:WikiProject Agriculture is - you could ask there. Chidgk1 (talk) 06:48, 11 March 2022 (UTC)

Rice tricky as also big cause of ghg as you know. Rice article editors on the ball I recall - suggest you ask there. Chidgk1 (talk) 06:54, 11 March 2022 (UTC)

What's your main argument for preferring wine and potato NOT to be sub-articles? Is it because the content is a bit outdated, it makes the content too hidden or because it sets a precedence for having lots of sub-articles for specific crops? I am undecided but am leaning slightly towards having sub-articles (but I agree that they should be shortened). Note that e.g. from potato it links to the sub-article here: https://en.wikipedia.org/wiki/Potato#Climate_change. I am also wondering if the information on adaptation should be grouped together under adaptation (which would speak against having sub-articles). - And I have now added an excerpt for rice. EMsmile (talk) 09:37, 11 March 2022 (UTC)

I supposed that they were not being kept up to date, so I thought being part of a more popular article might mean that they were updated more often. Chidgk1 (talk) 10:48, 11 March 2022 (UTC)

OK, I understand. Then I agree with you that sub-articles are currently not warranted, perhaps later. EMsmile (talk) 11:55, 11 March 2022 (UTC)

I removed the section on "crop development models"

I have removed this text block from the article as it was unsourced and overly detailed. If someone wants to rescue it please rework it and provide reliable sources: Models for climate behavior are frequently inconclusive. In order to further study effects of global warming on agriculture, other types of models, such as crop development models, yield prediction, quantities of water or fertilizer consumed, can be used. Such models condense the knowledge accumulated of the climate, soil, and effects observed of the results of various agricultural practices. They thus could make it possible to test strategies of adaptation to modifications of the environment.

Because these models are necessarily simplifying natural conditions (often based on the assumption that weeds, disease and insect pests are controlled), it is not clear whether the results they give will have an in-field reality. However, some results are partly validated with an increasing number of experimental results.

Other models, such as insect and disease development models based on climate projections are also used (for example simulation of aphid reproduction or septoria (cereal fungal disease) development).

Scenarios are used in order to estimate climate changes effects on crop development and yield. Each scenario is defined as a set of meteorological variables, based on generally accepted projections. For example, many models are running simulations based on doubled carbon dioxide projections, temperatures raise ranging from 1 °C up to 5 °C, and with rainfall levels an increase or decrease of 20%. Other parameters may include humidity, wind, and solar activity. Scenarios of crop models are testing farm-level adaptation, such as sowing date shift, climate adapted species (vernalisation need, heat and cold resistance), irrigation and fertilizer adaptation, resistance to disease. Most developed models are about wheat, maize, rice and soybean. EMsmile (talk) 12:20, 11 March 2022 (UTC)

Expand scope and rename to "Effects of climate change on agriculture and forestry"?

I am wondering if we should perhaps expand the scope of this article to "Effects of climate change on agriculture and forestry"? (I was even wondering if it should be expanded to "Effects of climate change on agriculture, fishery and forestry" but then I realised we already have effects of climate change on fisheries, and merging would make it too big. But linking is important as they both related to food security issues.) - I think the forestry aspect is not yet covered properly in another article though? EMsmile (talk) 10:27, 28 March 2022 (UTC)

Combining agriculture, fishery and forestry does mirror the structure in the IPCC Work Group II assessment. However, I agree that it probably makes it too large. I would suggesting having three separate "effects of climate change on..." pages. The forest one would clearly be linked from the more generic forest page. This might not work if there needed to be a lot of coverage of interaction, but that's not the case.

However,interactions between agriculture and forest is more critial when considering climate change mitigation. While not relevant to this page, I'm not sure that is currently well covered in the Climate_change_mitigation or other pages. 77.101.51.27 (talk) 09:27, 12 April 2022 (UTC)

Thanks for these inputs. I find that articles around "effects of climate change on XXX" tend to linger with low pageviews so my tendency these days is to not split them up too much. We could also start with adding forestry content and then later branch that off into a sub-article if it gets too big. What is the best literature to get this content from? The IPCC WG II report and also others? With regards to climate change mitigation it only mentions forestry three times. One of them is to branch off into here: https://en.wikipedia.org/wiki/Carbon_sequestration#Forestry . But I am not sure if that is sufficient, i.e. to only have it under "carbon sequestration"? Agriculture is mentioned more prominently in the "climate change mitigation" article and appears in the section on "Decarbonization by sector". EMsmile (talk) 11:29, 13 April 2022 (UTC)

ok, fair enough. "Effects of climate change on agriculture and forestry" could be renamed "Effects of climate change on land use", but actually think the more specific one is probably better.

If using IPCC as a source for forest mitigation option (which is a reasonable approach), it would be WGIII. The main chapter would be chapter 7 (https://report.ipcc.ch/ar6wg3/pdf/IPCC_AR6_WGIII_FinalDraft_Chapter07.pdf). PAlandus (talk) 10:48, 15 April 2022 (UTC)

Here in this article it wouldn't be about forestry + mitigation but more about how the yields from forestry might decline due to climate change. I know that e.g. forests in Germany are suffering from drought, heat waves, different pests and diseases already. Is that covered in detailed in the WG I or WG II report? I've also written about it here: https://en.wikipedia.org/wiki/Talk:Effects_of_climate_change#Reminder:_need_to_add_content_on_forestry I wonder if in the public perception it's all about "forests are great for mitigation" but people don't realise that the forests themselves will also suffer and change. EMsmile (talk) 10:57, 15 April 2022 (UTC)

Yes, you are quite right. WGII would be the one from the IPCC, specifically Chapter 5 (plus the regional chapters). PAlandus (talk) 21:13, 19 April 2022 (UTC)

I am still undecided about how best to tackle this. There are (natural) forests and then there's forestry. I found some text about the effects of climate change on forests here (article climate change and ecosystems): https://en.wikipedia.org/wiki/Climate_change_and_ecosystems#Forests . Content on wildfires and climate change are provided here: Wildfire. Then there is also an article on Forest dieback which contains some information. We'd have to ponder how to bundle this best so that readers can find the information easily and there's as little overlap across different articles as possible. EMsmile (talk) 09:37, 22 April 2022 (UTC)

Wiki Education assignment: Applied Plant Ecology Winter 2022

This article was the subject of a Wiki Education Foundation-supported course assignment, between 10 January 2022 and 23 April 2022. Further details are available on the course page. Student editor(s): Cf4095 (article contribs).

Review by content expert (April 2022)

We (myself and User:ASRASR) are currently working with content expert Peter Alexander to improve this article. He has sent me comments in a marked up Word document. This review is part of this project. EMsmile (talk) 11:29, 22 April 2022 (UTC)

Update: these comments have all been included in the meantime. EMsmile (talk) 09:50, 5 May 2023 (UTC)

Impacts on forestry

I have just removed this section for now as just a long quote from the IPCC report doesn't do this justice. Needs further work:

Impacts on forests and forestry

Further information: Forest dieback

The IPCC Sixth Assessment Report in 2022 found that: "In the past years, tree mortality continued to increase in many parts of the world. Large pulses of tree mortality were consistently linked to warmer and drier than average conditions for forests throughout the temperate and boreal biomes. Long-term monitoring of tropical forests indicates that climate change as begun to increase tree mortality and alter regeneration. Climate related dieback has also been observed due to novel interactions between the life cycles of trees and pest species." EMsmile (talk) 09:50, 5 May 2023 (UTC)

References

Reorganization: present and future

So, anyone who has seen this page before today will immediately recognize that significant changes have been done to it. I have actually started to work on this months ago, not long after finishing effects of climate change on livestock, but then put it off to focus on shepherding Thwaites Glacier and Permafrost through GA reviews. For a long time, those seemed more manageable than this page.

I know that other editors tend not to appreciate massive edits, so I tried to break up the completed page into a series of (still-large) edits. You can tell what I was going for from the edit reasons, but here's a recap:

• The layout of this page was very strange, and the sections had routinely mixed information about what happened only a few years ago with what is projected to happen later in the century. This confusion was the reason I couldn't edit the page more incrementally.

• The page was generally outdated, with nothing from AR6 or any of the notable papers from the last few years.

• When the IPCC was cited, it was in a very haphazard and dubious manner: i.e. the claim in the lead about food prices increasing 80% in 30 years, which did not seem to be even remotely present in the report cited.

• As the consequence of the above, the page was effectively unable to describe what the average reader likely cares about the most - the current projections/consensus with regards to hunger/malnutrition.

I have done the best I could regarding those, but I think it's clear notable issues remain.

• The attention certain topics receive seems rather haphazard. The size of the section on potatoes would have you believe they are the single most important crop, when most models do not even bother to track them. Early bloom section is also surprisingly large for saying little that's on-topic: phenology as evidence seems like it can be safely cut (not directly related to agriculture and we have other articles which talk about that), and it seems like disproportionate attention is given to a single NatGeo article, which is quoted at length. Weeds section is really dated, but the "land thawing" one is somehow even more so. Etc.

• Images. A lot more are needed, and some may need to be replaced as well (i.e. does the Fort Royal image even concern agriculture in any way, or is it general plant ecosystems research?)

• Regional impacts and adaptation sections are ultimately necessary, but so far, their structure appears rather...haphazard? In a lot of cases, I am really not sure if the examples chosen are even close to being the ideal when considering our all-too-limited article space.

InformationToKnowledge (talk) 18:24, 28 September 2023 (UTC)

OK, the lack of images is less acute now: though this article should still have more, a lot of the sections which currently lack images are the ones which, IMO, should be condensed heavily anyway, as they give undue attention to what are often secondary or even tertiary phenomena.

In that sense, I think it would be a good idea to merge "Loss of glacier-fed irrigation" with "Altered amount and variability of rainfall" as some sort of water resources section. Another idea would be to merge both "Agricultural land loss from sea level rise" and "Thawing of potentially arable land" into "Erosion and soil fertility", since all three are about the changes in agricultural land extent/quality. Finally, it seems like "Early blooms and effects on growing periods" should be merged into the "Increase in mean and extreme temperatures" (which already mentions growing seasons, after all) and "Weeds, invasive species and plant pathogens" somehow folded into the section right above it. However, a lot of the outdated/imprecise/not very relevant content would also need to be stripped out before such merges.

Then, I see now that the sections on wine and potatoes were this large because they were whole sub-articles before the merge. It seems like the hope (at least, of @Chidgk1) was that they would get updated more that way, but 1.5 years on, it doesn't seem like this is what has happened? Not that I would support splitting them back, though: I have moved most of the wine content to vitis vinifera, with a small excerpt left, and I would eventually want to do the same for the potato segment. (And the "crop adaptation" segments later on should likely be moved as well? Sadly, adaptation section is as woolly as in most other such articles.)

The only concern I would have about this, is that one could then argue the information on every crop should be moved there and then excerpted here. However, projections on wheat, maize, etc. are frequent and are far more likely to be seen by us than by whoever is maintaining the articles for those crops. I feel that the best approach would be to keep the information on the four major crops on this page and excerpt it on those crops' pages (that would mean moving the small excerpted section on rice to here), but doing the opposite for all the other crops, since the projections on them are published much less often.

Thoughts? InformationToKnowledge (talk) 16:04, 29 September 2023 (UTC)

The old structure was mainly set up by me. That doesn't mean I will be defensive over your changes. I agree with you that the article was in dire need of improvement and updating. But I am not sure your major split between "observed" and "predicted" works very well for many of the parameters. For example, there was previously a section like this:

• Direct impacts from increased atmospheric CO2 levels
  • Direct impacts from increased atmospheric CO2 levels subsection
  • Higher crop, grass and forestry yields due to CO2 fertilisation
  • Reduced nutritional value of crops

I think it was useful to keep these impacts separately from those caused by increased temperatures alone. Also, the information about "reduced nutritional value of crops" is not just predicted, it's already happening now and will get worse in future. Same for the others. Isn't everything that you have grouped under "Projected impacts by type" in fact already happening now? I would change that section simply to "Impacts by type". But then I don't know what sets it apart from the previous section on "observed impacts". For comparison, the old structure was like this for the first half of the article; it did not try to differentiate between observed and predicted (predicted for when? For in 5 years? For in 100 years? Those near time predictions will soon be the "present time"...):

• Direct impacts from changing weather patterns
• Direct impacts from increased atmospheric CO2 levels
• Climate driven changes in pests, plant diseases and weeds (indirect impacts)
• Other indirect impacts from changed conditions

Apart from that I find that in some parts there are now excessively long paragraphs. That makes for difficult reading. Can you look at improving that? Paragraph length should be about 4-6 lines long only (when the para extends over the whole page width). EMsmile (talk) 21:07, 29 September 2023 (UTC)

OK, how does the article look now?

My reasoning for the observed/projected split was that this is also what the IPCC does in AR6 and the other reports. Besides organizational purposes, the idea is that people tend to trust the already recorded observations more than the projections from models and other methods, so listing the former before the latter is more convincing. However, it seems like the report mainly does this for yields and the weather events, so I have now changed "observed impacts on ..." from a top-level heading to a subheading for those two sections as well, and restored the old structure for the CO2 subsection (albeit with a different title, and with methane/ozone folded into it.)

Pest/disease section is also a top-level section now, though I condensed and reorganized it where possible. I don't think it makes sense to have separate subheadings for specific pest insects, so I got rid of those, and instead split the section into better-defined subsections for insects, pathogens and weeds. (That section now seems markedly underwritten in comparison.) I have integrated all the potato diseases throughout as well.

The other indirect impacts were primarily about agricultural land, so that is now the new section heading. The only exception was phenology, and it was really poorly defined, so I kept it to a minimal reference in the "temperature" section. InformationToKnowledge (talk) 10:09, 30 September 2023 (UTC)

I only have a few minutes today to look at this but from a quick scan I conclude that I like your new structure a lot. Well done! I've just made some quick changes to make some section headings shorter / easier to understand. I know my changes makes them less accurate but I also know that long section headings are frowned upon. And e.g. the term "physiological" in a section heading is a little difficult, I would say. EMsmile (talk) 16:04, 30 September 2023 (UTC)

Article getting too long and use of excerpts

The article is nearly already too long now (57 kB (9073 words) "readable prose size"). So in general we should look for ways to condense information. I agree with the proposal made above to use excerpts whereever possible. Perhaps the information on adaptation for specific crops should rather be moved to that specific crop (e.g. for wine). It could then be brought back via an excerpt, or with just 1-2 sentences. The advantage is that the climate change info will then be included in those crop articles, i.e. integrated all over the place, not just located in this very specific sub-sub-article on climate change (I call it sub-sub article because effects of climate change is already the sub-article for climate change). EMsmile (talk) 21:18, 29 September 2023 (UTC)

I agree. Do you recall this WikiProject discussion from July? Wikipedia_talk:WikiProject_Climate_change#More_than_facts? I didn't participate in it back then, but in hindsight, I think the right key is to be as virtually omnipresent as our subject unfortunately warrants it. Which means that whenever data is available, there should be a subsection on every species article (obviously including crops, and also products from those crops where applicable), on every geographic location article, and a lot more besides that.

I have already made some steps towards that, like when I finally filled a notable gap in our coverage with effects of climate change on livestock, and then excerpted it on articles for the livestock species covered in it. Doing the same here can only be a good idea. For now, I have moved the rest of information on potatoes and wine to those articles. Rice is already an excerpt; for the other three major crops, those sections could probably be improved further before excerpting them. InformationToKnowledge (talk) 10:49, 30 September 2023 (UTC)

Where should the adaptation content mainly sit?

I am undecided if the adaptation+agriculture content should be mainly in this article and then transcribed to climate change adaptation or vice versa? In the adaptation article we have a section called "by sector": should this include a sub-section on agriculture? Pinging User:Richarit as someone who is knowledgeable on the adaptation topic. EMsmile (talk) 21:23, 29 September 2023 (UTC)

Well, the adaptation section in this article, as currently written, looks a lot in line with the adaptation article than this one (that is, mainly checking off vague proposals with distressingly few specifics). In that sense, I am inclined to say it would look better there.

However, simply transcluding it as "by sector" would seemingly result in an overlap with "Water" also treated as a sector, since that is mainly about irrigation. Perhaps there is an argument for a merge, but that is probably best for Richarit to decide.

Right now, adaptation section consists of five subsections, and my opinion on them is as follows:

• Changes in management practices - three vague sentences, and which are completely unreferenced as well.
• Agricultural innovation - has references, at least (albeit ones that are 10-14 years old), and is somewhat interesting, though still rather vague.
• Technological solutions to pests and weeds - this looks like the kind of thing which could be comfortably transcluded into "by type of impact" subsection?
• Institutional changes - I am not sure if there is any real difference between what this section and "Changes in management practices" are meant to say? It seems like we only need one of those subheadings?
• Climate-smart agriculture - an excerpt which can be included in either article. However; wouldn't it effectively encompass all the other subheadings as well? Isn't the ultimate purpose of both agricultural innovation and management/institutional changes to be "climate-smart" when in the context of climate change, as otherwise, we are simply going further into maladaptation?

In all, one could argue that a longer, modified excerpt from climate-smart agriculture would do the same thing as the entirety of the current adaptation section?

(I know that I had removed "Crop examples" from there recently, since wine section seemed to be a little superfluous for this article when more important crops are not represented, and the suggestions provided for potatoes ("plant in other areas" and "cultivate adapted varieties") could really be applied to any crop, and I am sure there is at least one article doing just that, which is what we should be referencing there instead.) InformationToKnowledge (talk) 11:16, 30 September 2023 (UTC)

Removed paragraphs on hail and phenology

Paragraph on hail:

In the northern United States, fewer hail days will occur overall due to climate change, but storms with larger hail might become more common. Hail larger than 1.6-inch can quite easily break glass, affecting greenhouses.

The way it is written is both really vague, to the point of resembling WP:SYNTH. Larger hail might become more common, and if it does, some completely unspecified fraction of which could "quite easily" break glass if it falls over greenhouses, which would occur...how often? And would cost...how much? The whole subject (changes to hail, and not just in the US, but globally) seems like it would be far better suited for effects of climate change on the water cycle, which is unfortunately far too small and seemingly undervisited, considering its actual importance.

This was the other section I removed.

Duration of crop growth cycles are above all, related to temperature. An increase in temperature will speed up development. In the case of an annual crop, the duration between sowing and harvesting will shorten (for example, the duration in order to harvest corn could shorten between one and four weeks). The shortening of such a cycle could have an adverse effect on productivity because senescence would occur sooner.

Changes in crop phenology provide important evidence of the response to recent regional climate change. Phenology is the study of natural phenomena that recur periodically, and how these phenomena relate to climate and seasonal changes. A significant advance in phenology has been observed for agriculture and forestry in large parts of the Northern Hemisphere.

Firstly, I would rather not use Google Books links in citations if at all possible. If the claim about senescense is even remotely reliable, it would be found in more accessible sources. Secondly, nearly everything to do with phenology would be much better suited for the overly short and badly dated phenological mismatch page. (And even then, that paragraph would need to be rewritten to rely on AR6 rather than AR4.).

References

InformationToKnowledge (talk) 11:20, 30 September 2023 (UTC)

Image selection

I think we should be approaching consensus about the article structure now, so any decisions about image placement should become clearer as well. I have the following opinions on the subject:

• Lead: the image appears a bit too regional to be used for the lead of a global article? I also don't think it's immediately clear that it shows the effects of climate change? The thumbnail was always on the smaller side as well, but it now appears even less suitable? I feel that it would be better to move it down to maize (currently lacking an illustration) as soon as we agree on a replacement. That replacement would either be some global-scale graphic (though not a map) that is really good and reasonably recent (i.e. not the AR4/NCAR ones later in the article) or a 2 x2 collage. If we go with the latter, then it would presumably cover one of each four main types of primary impacts: weather/streamflow changes, CO₂ changes, land erosion and insects/weeds/pathogens?

• Impacts from temperature: it would be nice to have some image there, but it seems like the section would require updating first, since most of the references are from 2004-2012? Once that's done, one of the newer studies would hopefully have a good graphic.

• Water availability - also an inconsistent mix of references. There is an image, but it could be better as well, I think? I would suggest moving it down to "Rice", but perhaps there are now better alternatives on Climate Visuals for that as well.

• Land extent: we can definitely find a suitable image from one of the three (for now?) subsections.

• Insects: I feel that this image is really unfortunate, because you kind have to squint to even see the locusts? A similar photo that's used on 2019–2022 locust infestation seems far more effective. If someone can find an aerial photo of the swarm, it would probably be the most impressive.

• Weeds: still hoping for something superior here?

• Plant pathogens: once either the weed section gets larger, or the image gets smaller, we can fit a crop infected with one of the climate-linked diseases there.

• IPCC/NCAR images: while rather old, it appears that a lot of the newer information of this kind is still paywalled, so they are probably still acceptable.

• Maize/rice: discussed above. We can probably find something for wheat, soybeans, potatoes and perhaps grapes and millet on Climate Visuals or elsewhere as well.

• Undernutrition & subsections: it's a large section, and I would like to find at least one more image of food security projections, but for now, most seem paywalled. A graphic for synchronized crop failures and another for labour impacts would be good as well.

• Regional impacts: every continent should probably have an image? I am also not sure if the current selections (Africa and North America) are really ideal?

• Adaptation: we may need a consensus on structure first. That last image probably needs a caption, at least, to explain what exactly makes it "climate-smart", and different from regular agriculture?

InformationToKnowledge (talk) 12:03, 30 September 2023 (UTC)

I am rushing today but just wanted to say for the lead image, my preference would be a 2 x 2 image collage, similar to the one at effects of climate change. Perhaps 3 images with crops plus 1 image with livestock? And 2 more Global North, 2 from Global South (or even one from Global North, 3 from Global South). EMsmile (talk) 16:06, 30 September 2023 (UTC)

Well, you can see the collage I went with. I think it succeeds at covering the four main impacts (water/erosion, heat, CO₂ and pests) but the layout isn't cooperating very well. It seems like the images would have to be resized to whatever is the closest average for all four (to reduce the number of artefacts to the minimum), so that the collage would show them all equally?

And as I have suggested before, I moved the old lead down to maize and the rice field image to rice. After quite a bit of searching, I was able to add what I think are pretty good images for nearly every section. The main exceptions are the erosion/soil fertility section and the adaptation/regional impacts sections, since all of them look rather out of date/with questionable focus, and it seems like that issue would have to be addressed first. InformationToKnowledge (talk) 11:18, 1 October 2023 (UTC)

Thank you. For the image collage in the lead, I think the two maps don't work well - they are not visual enough. I would replace them with photos. Also, let's not use that "clockwise" notation, I think User:Efbrazil had a good point here: https://en.wikipedia.org/w/index.php?title=Effects_of_climate_change&diff=1174145771&oldid=1173126704 where they said "Correcting image caption in lead to describe the images in the sequence they are seen on smartphone. Most of our viewers are on smartphone, so we need to use smartphone image sequencing and not say "clockwise" for galleries.") EMsmile (talk) 11:22, 2 October 2023 (UTC)

OK, I see the point about captions. As for the rest:

You are welcome to try and search Commons/Climate Visuals/etc. for alternate images. I have already tried, and the issue I found is that people mainly rush to photograph damaged infrastructure in the wake of disasters, and there are far fewer images showing anything agricultural than you would expect - and even less with the suitable licenses. Further, I would really want to use images from events that have been explicitly attributed to climate change (hence using flooding from that particular typhoon), and unfortunately, this reduces the available pool of images even further. InformationToKnowledge (talk) 15:03, 3 October 2023 (UTC)

When updating the link at effects of climate change after the collapse/apocalypse merge, I noticed that somehow, that page had the graphic with year 2500 projections, but this did not, so I had to correct that, and ended up shuffling many of the other images around. Those "multiple images" just don't tend to work with any sort of graphs or data, in my experience, so I ended up splitting them and spreading them more consistently throughout.

The flip side is that I moved the sidebar back up to the lead. I know you don't like this in general, but on this page, it slots in really well right under the collage, and I would rather have more images in the body of the article. InformationToKnowledge (talk) 14:36, 11 October 2023 (UTC)

I think the multiple image collage is OK for now but not quite ideal: I think maps don't work too well in an image collage as it requires too much thinking and reading for the reader. But for now I can live with this and don't have time to put my thinking cap on, so perhaps someone else wants to tackle this again in future. Thanks for all your work on this important article! EMsmile (talk) 08:02, 26 October 2023 (UTC)

Content about CO2 fertilisation

Moved from above: By EMsmile: "Also, I don't think the CO2 fertilisation effect needs to be depicted in the lead: from what I can gather it is rather minor, won't have much impact and is in fact probably outweighed by the lower amounts of some nutrients in those future crops (how to depict the changing nutrient content of certain crops in an image?)." EMsmile (talk) 20:37, 5 October 2023 (UTC)

Reply by InformationToKnowledge According to a last year's study (already cited on the CO2 fertilization effect page, and the source of what is now its page image), this effect had been increasing global productivity of croplands by 4-6% per decade (see this graph.) Another major review showed an average increase of 14%, with root crops increasing by 22% and some rice varieties increasing by 35% - all from a 200 ppm increase, which is still solidly in RCP 4.5 territory. None of those figures are minor in any realistic sense of the word. The main issue (in addition to micronutrients) is that C4 crops are largely unaffected, and maize, one of the big four, also happens to be one of those.

Sounds like the article CO2 fertilization effect is in dire need of updating then. What does the AR6 report say about the CO2 fertilization effect, is it really significant / overly "helpful" for humans? The studies that you quoted are "only" primary sources at this stage. My (limited) understand of the issues was that the modest "gains" for agriculture from climate change (such as potential for wine production in Sweden, more farming in Iceland etc.) are more than counteracted by all the losses for agriculture due to the extreme weather events etc. So on a global level, agriculture will be massively affected in a negative way. I think this should come out in the lead. But maybe my understand is wrong/outdated/not comprehensive. Pinging User:PAlandus who had helped us with the article in the past. Hoping he'll chime in again. EMsmile (talk) 15:32, 3 October 2023 (UTC)

I knew you would ask this:

Elevated CO 2 concentrations stimulate photosynthesis rates and biomass accumulation of C 3 crops, and enhance crop water use efficiency of various crop species, including C4 crops (high confidence) (Kimball, 2016; Toreti et al., 2020). Perennial crops and root crops may have a greater capacity for enhanced biomass under elevated CO 2 concentrations, although this does not always result in higher yields (Glenn et al., 2013; Kimball, 2016).

Recent FACE studies found that the effects of elevated CO 2 are greater under water-limited conditions (medium confidence) (Manderscheid et al., 2014; Fitzgerald et al., 2016; Kimball, 2016), which was generally reproduced by crop models (Deryng et al., 2016). However, drought sometimes negates the CO2 effects (Jin et al., 2018). There are significant interactions between CO 2, temperature, cultivars, nitrogen and phosphorous nutrients (Kimball, 2016; Toreti et al., 2020): positive effects of rising CO 2 on yield are significantly reduced by higher temperatures for soybean, wheat and rice (medium confidence) (Ruiz-Vera et al., 2013; Cai et al., 2016; Gray et al., 2016; Hasegawa et al., 2016; Obermeier et al., 2016; Purcell et al., 2018; Wang et al., 2018). In above-ground vegetables, elevated CO2 can in some cases reduce the impact of other climate stressors, while in others the negative impacts of other abiotic factors negate the potential benefit of elevated CO2 (Bourgault et al., 2017; Bourgault et al., 2018; Parvin et al., 2018;Parvin et al., 2019). Significant variation exists among cultivars in yield response to elevated CO2, which is positively correlated with yield potential in rice and soybean, suggesting the potential to develop cultivars for enhanced productivity under future elevated CO2(Ainsworth and Long, 2021).

Elevated CO 2 reduces some important nutrients such as protein, iron, zinc and some grains, fruit or vegetables to varying degrees depending on crop species and cultivars (high confidence) (Mattos et al., 2014;Myers et al., 2014; Dong et al., 2018; Scheelbeek et al., 2018; Zhu et al.,2018a; Jin et al., 2019; Ujiie et al., 2019). This is of particular relevance for fruit and vegetable crops given their importance in human nutrition (high confidence) (see Section 5.12.4 for potential impacts on nutrition; Nelson et al., 2018; Springmann et al., 2018). Recent experimental studies (Section 5.3.2), however, show some complex and counteracting interactions between CO 2 and temperature in wheat,soybean and rice; heat stress negates the adverse effect of elevated CO 2 on some nutrient elements (Macabuhay et al., 2018; Kohler et al.,2019; Wang et al., 2019b). The CO 2 by temperature interaction for grain quality needs to be better understood quantitatively to predict food

nutritional security in the future.

Two things to note here:

1) That PNAS study was published just after AR6, and so its findings could not have been taken into account by the text.

2) The conservatism of the IPCC, oft-maligned in certain circles, ultimately goes both ways, and I think this whole section is one example of just that. The second study I mentioned is cited (it's the "Ainsworth and Long, 2021" reference), but as you can see, they only chose to cite it in a rather narrow fashion which rather downplays their findings.

The combination of all the other negative effects does appear to overwhelm the effect's role in most cases (although wheat, and perhaps at least some rice varieties, may be the exception) - and the article already states as such. The point is not that the CO2 fertilization effect is "overly helpful" so much as that it is a massive stabilizing anchor without which things would have been considerably worse, a lot sooner. In that, it certainly deserves to be placed in the lead, and in the collage. InformationToKnowledge (talk) 16:17, 3 October 2023 (UTC)

Received the following info from Peter Alexander about this via e-mail: "The questions on CO2 fertilisation is really interesting, but hard to answer. I think the discussion on the Talk page is good. Personally, I’m sceptical about the finding of 4-6% yield increase per decade from that effect in crops, although that does seem a reasonable conclusion from the PNAS study. Data from earth observation are always going to be difficult to disaggregate crop breeding and land management from CO2 fertilisation. Also, I work with LPJ-GUESS (although admittedly not directly) and am also not convinced that DGVM models (dynamic global vegetation models) are capturing this well either. I think that IPCC text strikes a better balance of the uncertainties and complexities involved than suggesting 4-6% increase per decade. Certainly, including CO2 fertilisation in this page is appropriate, but nonetheless the message is that on balance globally the impacts will be negative."

And from further discussions amongst colleagues: "Anyway, can't you write that co2 response in crops exists but that magnitude remains uncertain? I know that ideally you link then to another paper that arrives at less than 4-6 prc per decade. But even saying that there are methodological issues and whether results of 4-6 perc are too optimistic is an open issue. Or is that too academic?" and "The analysis seems to indicate it but it is indeed difficult to believe globally. They seem to have combined a mix of modelling (and the models may well be too optimistic, and are notorioulsy bad at modelling crops -- just consider the simplistic way LPJG does it, and we're probably one of the better DGVMs in that respect). But satellite derived estimates -- how would they differentiate between breeding and CO2? So the overall GPP trend is maybe ok in the analysis, but I personally would be careful about the crop response in particular..." EMsmile (talk) 20:42, 5 October 2023 (UTC)

This is really interesting; thanks for making the effort to reach out and share this! Did Peter Alexander comment on anything else in regards to recent changes to the article, by any chance?

For now, that particular 4-6% figure is not yet included in either the fertilization article or in this one. For now, I am unlikely to rush to edit those, as I still consider the sections on regional impacts, adaptation, weeds, soil fertility and arable land thaw to be far more problematic and in need of much greater attention. Once I do get to those articles, I'll keep these commments about balancing out that figure with another paper in mind. InformationToKnowledge (talk) 14:58, 6 October 2023 (UTC)

No, he didn't have time to provide feedback on the rest of the article. Perhaps if we have specific questions to him (like the CO2 fertilisation question), he'll make the time to answer those. Last year in March and April 22 he had given the then-current version quite a detailed review and that was super helpful. It's great to work with someone who is really knowledgeable on this subject. This is how the article looked in March 2022 before I began the review work and before Peter got involved: https://en.wikipedia.org/w/index.php?title=Effects_of_climate_change_on_agriculture&oldid=1075697309 . It's come a long way since then and I am super happy that you were able to give it another overhaul now! EMsmile (talk) 21:11, 6 October 2023 (UTC)

Observations on the new lead

The new lead reads like an interesting "story" but it's almost like it contains some WP:OR, the way the statements are strung together. Also, it doesn't follow the Wikipedia guideline that the lead should be a summary of the main text (WP:LEAD). Especially these two paragraphs are in the lead but I could not easily find this content in the main text (did I overlook them in the main text?):

+++++++++

Altogether, there is a consensus that global food security will change relatively little in the near-term: 720 million to 811 million people were considered undernourished in 2021 (of whom 200,000, 32.3 million and 112.3 million people were at a "catastrophic", "emergency" and "crisis" levels of food insecurity, respectively). Compared to that figure, 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). Continued economic and agricultural development will likely improve food security for hundreds of millions of people by then.

Another estimate from 2016 suggests that around 529,000 people could die between 2010 and 2050 due to the impacts of climate change on food supply. The majority of these deaths would be caused by the lack of micronutrients from reduced fruits and vegetable supply, rather than outright starvation. A range of scientists have voiced concerns about the impact of currently-unprecedented extreme weather events in the future climate. Further-future research (to 2100 and beyond) is rather limited. In any case, there is no expectation of a widespread global famine in published scientific literature, in contrast to some speculation. +++++++

Overall, I think the lead has become a bit too long and detailed now. It's now 658 words long. My recommendation would be to bring it back down to 500 words. I also found many sentences too long (for readability, for people who do not have university degrees and are not native English speakers). Sentences that have a construction of "while this is true xxx, this is also the case xxx", can often be broken into two rather. I've already done that for some of the long complicated sentences but more needs to be done.

I would enjoy reading the lead in its current format if I came across it in a scientific publication but to meet our needs for a Wikipedia article lead, it needs a little bit of tweaking. This shouldn't be very time consuming. E.g. move some of the detailed content into the main text and then just leave summary statements in the lead. EMsmile (talk) 20:49, 30 September 2023 (UTC)

I mean, you have already edited the section on food security and undernutrition, so I'm surprised you could not find how it corresponds with that part of the lead. The sentence about the year 2016 study with the 529,000 deaths figure is practically the same between the lead and that section. The 8 to 80 million people figure, is of course, from the AR6 (and no, I do not think reducing its estimate to another yet "scientific studies" is a good idea!) You can see correlations between the other sentences in the lead and that section based on the shared references.

The only thing which wasn't present at first was the year 2021 figure, as that section used a year 2017 figure instead and I was concerned including both could make the section look even more bulky. Now, though, I think I was able to include it while simplifying a different sentence. InformationToKnowledge (talk) 11:55, 1 October 2023 (UTC)

I found that bit later, yes. Still, I think the lead is far too long and detailed now and in some parts not a very good summary of the entire article overall. It should summarise content from each part of the main text (ideally), whereas you have now devoted a lot of space in the lead to summarising/repeating content from the section called "Global food security and undernutrition". Hence, I think the lead is a bit unbalanced now and reads more like a "story" rather than a summary. Regarding not mentioning IPCC AR6 explicitly more often than absolutely necessary see here for a previous discussion: https://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Climate_change/Archive_4#Explicitly_mentioning_the_IPCC_report (I was originally against it (meaning I was one of the people who explicitly mentioned the IPCC quite often but have since changed my mind). In effect, the AR6 is just a very well curated literature review, not its own (new) study. (I am rushing a bit today, so this is just a quick response, on my way out). EMsmile (talk) 10:21, 2 October 2023 (UTC)

Well, for a lot of readers, that section would be the most important one in the article. Sure, it's great to describe the effects on various facets of agriculture, but ultimately, isn't the main point to know how those effects will then actually change people's lives? So, the lead should definitely devote enough space to cover those findings. If you would like to cut something from it, what would it be?

And to me, the point of mentioning the IPCC specifically in that section was to avoid its projection looking out of context otherwise. After you edited it, the section went from "a meta-analysis of 57 studies says this" straight to "some unclear scientific studies say something seemingly different" (though not necessarily so). Writing it like this makes it seem like the first finding is much weightier and more prominent than the second, even though that's likely not the case: the IPCC finding was definitely seen by a lot more people around the levels of power, at any rate. In this particular case, I don't think the people would understand why its projection is important if we do not name the source. InformationToKnowledge (talk) 10:57, 2 October 2023 (UTC)

OK, change it back to mentioning the IPCC if you feel strongly about it. But you saw here that it's frowned upon by some. This is partly because some think the IPCC reports are not so reliable but also just a bunch of scientists as well (of course you and I know that is wrong). So if it was me, I would change the wording of both sentences so that the IPCC content comes across as more definitive, without having to mention IPCC. - Regarding "isn't the main point to know how those effects will then actually change people's lives", I don't think it's the job of the lead to make this "main point". It's meant to summarise the article in all its facets. If you feel strongly about the food security aspects, I suggest you/we also pay some attention to the food security article to check what it says about climate change there. EMsmile (talk) 11:28, 2 October 2023 (UTC)

I've made some changes to that particular paragraph now which I think made the main conclusions clearer and removed some detail that is not needed in the summary-style lead. The lead is now 589 words long which I find still about 100 words too long. So some detailed content here and there could still be cut, especially if room needs to be made for some sentences that summarise parts of the main text that are not yet summarised in the lead at all. (I still think the content about food security aspects is a bit too long for a lead) EMsmile (talk) 11:45, 2 October 2023 (UTC)

Thanks for reminding me of that article. At first glance, it's not as dated/speculative as it could have been, though it can clearly be improved further.

I think your changes to the lead have largely been successful - although I still made more than a few alterations. Altogether, the lead has been shortened further - though the reductions all came from sections other than food security, and it is still 50 or so words off your target. However, I would like to note that this article is nearly as long as sea level rise (perhaps longer, if you count the text in excerpts), yet its lead is around half its length. Sure, the sea level rise article is quite an anomaly, but its existence does add context. InformationToKnowledge (talk) 15:54, 3 October 2023 (UTC)

It's better now, thanks. Regarding length of articles and lead length, I wouldn't compare it with an arbitrary article (like sea level rise) but only with FA articles. A good one to compare with is the one on climate change. If this article (which could have become huge) managed to stay succinct and on focus (55 kB (8528 words) "readable prose size") with a lead of around 500 words length, then I think this is a good model to follow. Or maybe an argument can be made that a sub-sub-article could be made more detailed than a high level article but I am not sure about the validity of that argument. EMsmile (talk) 20:33, 5 October 2023 (UTC)

Well, if sea level rise is an arbitrary example, isn't the 500-word target a little arbitrary as well: an artefact of our subconscious propensity to prefer nice, round numbers? I think the lead is around 550 words now, and I really like how it looks. I am just not convinced that shedding 50 more words or thereabouts would really be a great improvement and not come at the expense of important details. At this point, I think dealing with the remainder of outdated/poorly structured content (i.e. practically the entirely of regional and adaptation sections, as already discussed above) is far more important than making further tweaks to the lead. InformationToKnowledge (talk) 14:49, 6 October 2023 (UTC)

Regarding the length of the lead, the figure of 500 words might be somewhat "arbitrary" but the number of paragraphs is not. I prefer 4 paragraphs in the lead (and each para about 4-6 lines long, as a rule of thumb). This is in line (possibly even slightly longer) than the recommendation you find in the Manual of Style here: https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Lead_section#Length .

My other observation that I had made above was not about just the length but also that in parts it was overly detailed, rather than a summary style text (this has been improved now). In comparison, the last paragraph about adaptation is a good example of "summary style wording". But yes, I agree with you, no point spending time at this point to shed another 50 words from the lead. Hope to get around to helping with this article further at some point in the future but not sure when I'll find the time. We need more helpers. EMsmile (talk) 21:05, 6 October 2023 (UTC)

I've worked a bit on improving the reading ease score of the lead (using the readability tool to point me to difficult sentences). I hope I succeeded in making the lead easier to understand without changing the meaning or losing too much detail. I took out the last paragraph about adaptation because I felt it was rather waffly, and perhaps OK for the main text but not for the lead. As adaptation is not the core topic of this article, I felt we didn't need that paragraph about adaptation in the lead. EMsmile (talk) 20:09, 9 April 2024 (UTC)

Effects of desertification

This article does not mention effects of desertification due to climate change. Is climate change expected to have a significant effect on agriculture due to desertification?

Desertification is also not mentioned in this article about the effects of climate change on the water cycle. Jarble (talk) 23:15, 29 February 2024 (UTC)

Well, desertification should logically be mentioned in the sub-section on erosion: however, that is one of the sections I didn't have time to look at in depth when reorganizing this article in September-October, so unfortunately, it isn't there.

Having said that, desertification also didn't get much mention at all in the agricultural section of IPCC AR6 WG2, which was one of the main references I used for reorganizing this article. The reason is because climate change increases the net amount of rainfall worldwide: a point already clearly made in the corresponding sub-section of this article, though perhaps not in the water cycle article, which receives surprisingly few views and so has not been a priority for improvement.

Consequently, desertification is actually going the other way around across much of the globe for now. Here is the IPCC AR6 WG2, page 2197:

Multiple lines of evidence from 1920–2015 indicate that surface warming of 1.2°C–1.3°C over global drylands (Section 1.1.1) exceeded the 0.8°C–1.0°C warming over humid lands. From 1982 to 2015, unsustainable land use and climate change combined caused desertification of 6% of the global dryland area, while 41% showed significant increases in vegetation productivity (greening) and 53% of the area had no notable change, although greening rates are slowing or declining in some locations.

Same page:

Some drylands will expand by 2100, while others will shrink (high confidence). Climate change affects drylands through increased temperatures and more irregular rainfall, with important differences between areas with different rainfall distributions linked to the dominant climate systems in each location. Projections are nevertheless uncertain and not well supported by observed trends, while different methodological approaches and indices exhibit different strengths and weaknesses (medium confidence).

Page 2200:

Based on the AI [note:Aridity Index], some drylands are projected to expand and othersto contract due to climate change. However, there is no evidence of a global trend in dryland expansion based on vegetation patterns, precipitation and soil moisture, based on the satellite record from the 1980s to the present (medium confidence). The AI will also be of limited use under a changing CO2 environment due to higher water use efficiency by some plants (Mirzabaev et al., 2019), and it overvalues the role of potential evapotranspiration (PET) relative to rainfall. It also does not account for CO2 impacts on evapotranspiration, and seasonality in rainfall and evapotranspiration.

For Africa, on page 1332:

The overall continental trend is woody plant expansion, particularly in grasslands and savannas, with woody plant cover increasing at a rate of 2.4% per decade (see Figure 9.17; Stevens et al., 2017; Axelsson and Hanan, 2018). There is also increased grass cover in arid regions in southwestern Africa (Masubelele et al., 2014). There is high agreement that this is attributable to increased CO2, warmer and wetter climates, declines in burned area and release from herbivore browsing pressure, but the relative importance of these interacting drivers remains uncertain (O’Connor et al., 2014; Stevens et al., 2016; García Criado et al., 2020). Woody encroachment is the dominant trend in the western and central Sahel, occurring over 24% of the region, driven primarily by shifts in rainfall timing and recovery from drought (Anchang et al., 2019; Brandt et al., 2019). Remote sensing studies demonstrate greening in southern Africa and forest expansion into water-limited savannas in central and west Africa (Baccini et al., 2017; Aleman et al., 2018; Piao et al., 2020), with increases in precipitation and atmospheric CO2 the probable determinants of change (Venter et al., 2018; Brandt et al., 2019; Zhang et al., 2019). These trends of greening and woody plant expansion stand in contrast to the desertification and contraction of vegetated areas highlighted in AR5 (Niang et al., 2014), but are based on multiple studies and longer time series of observations. Reported cases of desertification and vegetation loss, for example, in the Sahel, appear transitory and localised rather than widespread and permanent (Dardel et al., 2014; Pandit et al., 2018; Sterk and Stoorvogel, 2020).

So, AR6's comments on desertification and agriculture are less far-reaching than you might expect.

Page 2209:

Rising temperatures, variation in rainfall patterns and frequent extreme weather events associated with climate change have adversely affected agro-ecological food systems and pastoral systems in some drylands (Zhu et al., 2013; Amin et al., 2018), especially in developing countries (Haider and Adnan, 2014; Ahmed et al., 2016; ur Rahman et al., 2018) where desertification is a key challenge to agricultural livelihoods. Recurrent droughts in recent decades, coupled with wind erosion (particularly of fine sediment which gives soil its water-holding capacity and nutrients), affected vast areas in Argentina, leading to land abandonment and agricultural fields being covered by sand and invasive plants (Abraham et al., 2016). Temperature increases have contributed to reduced wheat yields in arid, semiarid and dry sub-humid zones of Pakistan (Sultana et al., 2019). Agricultural production in the drylands of South Punjab is experiencing irreversible impacts since the grain formation phase has become swifter with a warmer climate, leading to improper growth and reduced yields (Rasul et al., 2011). Aslam et al. (2018) regard climate change impacts as particularly threatening to the livestock sector, water and food security, and the economy beyond agriculture in South Punjab, particularly as yields decrease. In the livestock sector across global drylands (WGI TS.4.3.2.10), observed impacts include reduction of plant cover in rangelands, reduced livestock and crop yields, loss of biodiversity and increased land degradation and soil nutrient loss (Van de Steeg, 2012; Mganga et al., 2015; Ahmed et al., 2016; Mohamed et al., 2016; Eldridge and Beecham, 2018, Arias et al., 2021), as well as injury and livestock death due to SDS. This is particularly worrisome for traditional pastoralists who find themselves with fewer safety nets and more limited adaptive capacities than in the past, particularly where mobility, access and tenure rights are becoming restricted (Box CCP3.1) and where use of technologies such as mobile phones can result in mixed effects, as found in Morocco (Vidal-González and Nahhass, 2018). Observed SDS impacts can increase food production costs and threaten sustainability more generally (Middleton, 2017). Woody plant encroachment and greening may be masking underlying land degradation processes and losses of ecosystem services, livelihood and adaptation options in pastoral livelihood systems (Reed et al., 2015; Chen et al., 2019a). Woody encroachment alters ecosystem services, particularly in rangelands, resulting in reduction of grass cover, hindering livestock production (Anadón et al. 2014), reducing water availability (Honda and Durigan 2016, Stringer et al., 2021) but increasing availability of wood (Mograbi et al., 2019).

Page 2213:

Projected impacts of climate change on the risk of food insecurity are a particular concern for the developing world drylands (Chapter 16; Mirzabaev et al., 2019), potentially leading to the breakdown of food production systems, including crops, livestock and fisheries, as well as disruptions in food supply chains and distribution (Myers et al., 2017; Lewis and Mallela, 2018). Developing country drylands are particularly vulnerable due to a higher share of populations with lower income, lower physical access to nutritious food, social discrimination and other environmental factors that link to climate change. For example, countries such as Somalia, Yemen and Sudan faced recent and resurging challenges from an increase in desert locusts, the effects of which, in 2020, extended from East Africa through the Arabian Peninsula and Iran as far as India and Pakistan. Meynard et al. (2020) note that under climate change, some areas suffering from previous outbreaks may see changes in formation of swarms of Schistocerca gregaria. Salih et al. (2020) recognise that attributing the 2020 swarms as a single event to climate change remains challenging, but highlight that projected temperature and rainfall increases in deserts and strong tropical cycles can create conditions conducive to the development, aggregation, outbreak and survival of locusts. Mandumbu et al. (2017) highlight how crop parasites such as Striga spp. in southern Africa may benefit from higher temperatures and rainfall activating dormant seeds, while high winds aid their dispersal. Combined with increasing risks of erosion and soil fertility losses (Striga is able to tolerate drought and a low nitrogen environment), this can have important impacts on the yields of key dryland crops such as maize and pearl millet.

The only areas where I have seen hard negative impact numbers related to desertification was for Europe,

Page 1823: 9% of Europe’s population was projected to be exposed to aggravated water scarcity, and 8% of the territory of Europe were characterised to have a high or very high sensitivity to desertification

And for South and Central America.

Page 1697:

These processes are leading and will continue to lead to increased desertification that will cost between 8% and 14% of gross agricultural product in in many CSA countries.

Page 1709, on Northeast of the continent (basically Venezuela, North Brazil, and the three small coastal countries.)

NES is home to about 60 million people, with >70% living in urban areas (data for 2010 from IBGE [2020]; Silva et al. [2017]) and high poverty levels (>50%, data for 2003 fromIBGE [2020]]). People are exposed to intense drought and famine (high confidence), and about 94% of the region has moderate to high susceptibility to desertification

It'll take some time to think of the best way to integrate this. InformationToKnowledge (talk) 07:03, 1 March 2024 (UTC)

Interesting. Thanks for putting this information together! Maybe desertification is more relevant in the context of this article: Deforestation and climate change‎. Deforestation can lead to desertification and thus makes it harder to do reforestation later and hence a lost opportunity for carbon sequestration? EMsmile (talk) 19:18, 19 March 2024 (UTC)