Talk:Climate change

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Effects on humans with respect to Climate Security/Tipping Points/4C warming

We need a paragraph or two about these topics in Humans subsection under Effects section. This was my previous suggestion:

Climate change has also been called a security threat. US intelligence analysts have expressed concern about the "serious security risks" of climate change since the 1980s. The Pentagon has also released a report stating that climate change is a national security threat to USA. Moreover, the available evidence suggests that scientists have underestimated the impacts of climate change in their projections. Exceeding tipping points can also bring abrupt and irreversible climate changes which could be an existential threat to civilization.

Additional sources: [1], "Warming of 4°C or more could reduce the global human population by 80% or 90%,35 and the World Bank reports “there is no certainty that adaptation to a 4°C world is possible”" [2], "The broad consensus in the literature is that expected damages caused by unmitigated climate change will be high and the probability of catastrophic tail-risk events is non-negligible...There is growing agreement between economists and scientists that the tail risks are material and the risk of catastrophic and irreversible disaster is rising, implying potentially infinite costs of unmitigated climate change, including, in the extreme, human extinction" IMF Bogazicili (talk) 22:57, 7 October 2020 (UTC)

Thanks for your suggestions. Having an entire paragraph dedicated to security is exaggerated. The scientific literature on climate security is significantly less certain about those links as you suggest. the first sentence suffers from having weasel words. As this is a live scientific debate, I think review type articles that are peer reviewed are the only high quality sources we should be using. Also, why focus on the single country that only accounts for a small percentage of worldwide population?

Saying that scientists have underestimated impacts may be true, but the source is from 2013. Maybe in the meantime (and I don't really think so) we have overestimated impacts. I don't think a statement like that is sufficiently important for this article, but if there is consensus to include, it should be cited to a more recent source. I'd say that climate change being an existential threat is a significant minority view among scientists, and the wording is correct using the word 'could'. I'm okay to be overruled on that point if other editors believe this is not neutral.

The statement of 80 to 90% is sourced to a PowerPoint presentation... The source talking about human extinction doesn't back that up at all. They cite a source that talks about the extinction of civilisation and incorrectly translate that to a far more radical statement of human extinction. Femke Nijsse (talk) 06:46, 8 October 2020 (UTC)

I agree that the suggested additions will detract from the validity of the article. A single sentence talking about the US military could be helpful though- both talking about its own climate impact / mitigation efforts (there were some efforts under Obama) and the geopolitically destabilizing impacts of climate change. Efbrazil (talk) 15:32, 8 October 2020 (UTC)

talking about the US military in terms of mitigation is clearly undue, right? There are way bigger sectors out there. The geopolitically destabilising impacts of climate change should be attributable to an actually neutral source. My feeling is that the Pentagon will not be perceived as neutral by most people in the Middle East, nor in Europe. Femke Nijsse (talk) 15:46, 8 October 2020 (UTC)

Poking the Internet, it looks like about 10% of US emissions directly come from the US military, although it is the primary supplier of weapons systems worldwide and has negative impacts like construction and power use that I don't think are factored into that 10% number. The value in raising the topic of the US Military, as I see it, is to reach people that are viewing the article from that frame of reference- people in the military or concerned with geopolitical stability. If the US military is trying to solve global instability caused by CO₂ emissions, it should be taking the lead on the mitigation issue. In terms of source, if the source is critiquing the military it could be more reliable if it actually comes from the military itself. Efbrazil (talk) 16:44, 8 October 2020 (UTC)

you have been talking about removing bias ( always funny that liberals are left-wingers in the US, but centre-right in Europe), and this feels like an insertion of such bias. Were not trying to convince anybody, and our overview sources do not single out the US military. We don't mention other sectors of the economy of a single country. Femke Nijsse (talk) 19:18, 11 October 2020 (UTC)

I'll break down the issues to keep focused on where agreement lies: Bogazicili (talk) 01:15, 12 October 2020 (UTC)

Tipping Points/4C warming

1) I guess everyone agrees mentioning this?

2) Femkemilene said "climate change being an existential threat is a significant minority view among scientists, and the wording is correct using the word 'could'". So I think we can agree to add this along with the scientific consensus (from IMF: "The broad consensus in the literature is that expected damages caused by unmitigated climate change will be high and the probability of catastrophic tail-risk events is non-negligible"). I'm looking for more sources about this.

3) Note that even some scientist that do not agree with existential threat still see massive damage:

"Johan Rockström, the head of one of Europe’s leading research institutes, warned in 2019 that in a 4°C-warmer world it would be “difficult to see how we could accommodate a billion people or even half of that … There will be a rich minority of people who survive with modern lifestyles, no doubt, but it will be a turbulent, conflict-ridden world”." [3]

"Why terrifying? As Professor Kevin Anderson, a leading climate scientist at the University of Manchester, said: “There is a widespread view that a 4C future is incompatible with an organised global community, is likely to be beyond adaptation and be devastating to the majority of ecosystems.” In other words, a world where food crops would collapse, billions could starve, governments collapse and coastal cities flood, making hundreds of millions homeless." [4]

So basically, three sentences for this: scientific consensus of massive damage, opinions of likes of Rockström and Anderson, existential threat to civilization (from Nature article). Does this reflect the accurate viewpoints of scientists? I'm just looking for best sources to construct this part. Bogazicili (talk) 01:15, 12 October 2020 (UTC)

1. I think the IMF quote or paraphrasing it would work best to show the possibility of massive damage
2. I think including individual opinions isn't even appropriate for subarticles of this topic, so no to that one.
3. I would like to have input from other editors about including a sentence about an existential threat to civilisation, as this is quite a tricky one. Efbrazil, Dtetta, RCraig09?. Femke Nijsse (talk) 17:30, 13 October 2020 (UTC)

1) Ok then we agree. Do you also agree with catastrophic tail-risk events part (we can paraphrased tail risk)?

2) Well, we have "untold suffering" [5] from more than 11,000 scientists and "widespread misery" from 15,364 scientists.[6]. We cannot ignore these sources.

3) It's from here [7] Bogazicili (talk) 03:37, 22 October 2020 (UTC)

Another highly cited paper linked above [8], 1050 citations (2018 paper) [9]:

"with serious challenges for the viability of human societies."

We have enough material for a sentence such as "could be an existential threat to civilization[10] or challenge the viability of human societies[11]" Bogazicili (talk) 11:10, 23 October 2020 (UTC)

Apologies, just saw this request for input. I need to take a day or so to review the sources...will post a response by 24 Oct.Dtetta (talk) 04:56, 23 October 2020 (UTC)

Dtetta, just added more stuff above, after your response.Bogazicili (talk) 11:10, 23 October 2020 (UTC)

I’m glad Bogazicili has raised the issue, and some of his references may be useful here, but I’m concerned about cherry picking specific web articles or papers. It seems like the question here is how best to revise the two current tipping point paragraphs, and to what extent the paragraphs should discuss/emphasize hothouse earth type scenarios, or other cataclysmic possibilities. Personally, I think the tipping point paragraphs could be improved a bit, but I would prefer to see our efforts focus on a better discussion of more specific reasonable worst case 2050 and 2100 scenarios in the other parts of the effects section. I think recent studies are now discounting the 4C scenarios as a little less likely, so I think more emphasis on 2C and 3C scenarios would be more useful to readers.Dtetta (talk) 21:50, 24 October 2020 (UTC)

What? There are no tipping point paragraphs in Humans subsection currently. That's the whole issue. Bogazicili (talk) 02:54, 25 October 2020 (UTC)

I understand there is no tipping points discussion in the current Humans subsection. My point is that I think that subsection would be better served by more clearly describing reasonable worst-case-scenario effects at 2C and 3C. As it is right now the wording has been revised from what I wrote in early September (Archive 83 Section 9) in a manner that downplays the effects. So it seems counterproductive to downplay the most likely effects and then end with some sort of cataclysmic statement, even though that statement might be supported by certain reliable sources. I think that juxtaposition detracts from the credibility of the article.Dtetta (talk) 03:18, 25 October 2020 (UTC)

Can you post your updated wording for "reasonable worst-case-scenario effects at 2C and 3C" here again?

Because what you wrote earlier has a lot of strikethrough's and some of it is already in the article, so not sure what would be your current suggestion to add into Humans subsection.

I'd still like to add once sentence about "could be existential threat" or "viability of human societies". We have so many sources saying something similar in this vein.Bogazicili (talk) 03:58, 25 October 2020 (UTC)

climate change induced mortality

I don't have specific suggestions at present; my point was that this is something that should be worked on, preferably in a collaborative way. If you look at the Wayback Machine for Climate Change, and go to one of the Sep. 9 archives, you can see the original text when this subsection was revised based on the talk page proposal I made. In particular, I think the editing downward of the sentence describing estimated annual deaths is an example of what I was saying in my earlier comment about downplaying the effects.Dtetta (talk) 15:58, 25 October 2020 (UTC)

I see. The downward revision was made by Efbrazil on September 15 [12]. Efbrazil, can you explain your edit??

Here's what WHO says:

"Between 2030 and 2050, climate change is expected to cause approximately 250 000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress." [13]

Here's what the original source said:

"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." [14]

These are completely different things. The Lancet study ("529 000 climate-related") is only due to dietary change, and does not include things like malaria, diarrhoea and heat stress (although there might be overlap with malnutrition).

If no objection, I'll add this information in addition to the current information, as they are two different things.

We also have a new paper, but it's not peer reviewed yet. Could be added if and when it does get reviewed:

"A new analysis published this week by the National Bureau of Economic Research suggests that, if left unchecked, climate change could drive temperatures up to the point where they would lead to 85 deaths per 100,000 people globally per year by the end of the century. That’s more than are currently killed by all infectious diseases across the globe." [15] Bogazicili (talk) 00:24, 29 October 2020 (UTC)

Actually, in the last sentence of the second paragraph that I wrote, in the wording I was trying to capture both the WHO and Lancet studies. Both are included in the citation at the end of the sentence. I thought that wording actually addressed both, but if you want to propose an alternative wording here I’m fine with that.Dtetta (talk) 06:14, 29 October 2020 (UTC)

I think the current wording should stay. The following sentence should be added into third paragraph (which became food and water paragraph)

"By 2050, changes in global food availability alone due to climate change (business as usual scenario) will be associated with 529 000 annual deaths."

This is RCP8.5 by 2050 though. Femkemilene, what do you think? It's a primary source, but it's a novel methodology study from 2016. Would be hard to find a review article on this topic I think.

Also, this is my suggestion for what Dtetta said, I still think we should have an additional sentence for tipping points etc.Bogazicili (talk) 08:15, 30 October 2020 (UTC)

Dtetta, I actually found a secondary source for 529 000 number and added it into the Humans section. What I added is bolded:

"World Health Organization (WHO) has estimated that between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year, from malnutrition, malaria, diarrhea and heat stress.[172][173] This is a conservative estimate, as it does not include deaths due to other related reasons. For example, additional 529,000 adult deaths are predicted worldwide, due to expected reductions in food availability.[173]"

This is a good review article/secondary source as it makes it clear that 250,000 and 529 000 numbers come from two different things. Here's what the article says:

"The World Health Organization (WHO) estimated that approximately 250,000 deaths annually between 2030 and 2050 could be due to climate change–related increases in heat exposure in elderly people, as well as increases in diarrheal disease, malaria, dengue, coastal flooding, and childhood stunting.16 This is a conservative estimate, because it does not include deaths from other climate-sensitive health outcomes and does not include morbidity or the effects associated with the disruption of health services from extreme weather and climate events. For example, a climate change–associated net increase of 529,000 adult deaths worldwide (95% confidence interval [CI], 314,000 to 736,000) was projected to result from expected reductions in food availability (particularly fruit and vegetables) by 2050, as compared with a reference scenario without climate change." Haines, Andy; Ebi, Kristie (2019-01-16). "The Imperative for Climate Action to Protect Health". New England Journal of Medicine. doi:10.1056/nejmra1807873. Bogazicili (talk) 17:09, 5 November 2020 (UTC)

that new source seems valuable, thanks for finding it. The current two sentences in our article are contradictory, as we do attribute those 250,000 deaths to malnutrition, which is different from the paper in the new England journal of medicine. I delved into the 2014 WHO report (which is the source of these numbers), and apparently they only include malnutrition of children under the age of five. The World Health Organisation website isn't a great source, as it doesn't even include a pointer to the actual scientific source making specific scientific claims.

• I think I'm repeating myself if I say my preferred solution doesn't include any numbers, as uncertainties around those are too big and I don't really feel that people have a sense of what these numbers mean anyway. I will fight any crime against significant numbers (no way the researchers can estimate mortality to 3 different significant digits)
• I would also like the paragraph to be shorter, so that there is no undue emphasis on health. I think the best candidate for removal is the new sentence about social factors which is quite vague. I will make the new addition of mortality less wordy.
• If we go for a solution with numbers we probably want to cite the WHO report directly, in addition to the new source. My accessibility software is horrible for these type of citations, Dtetta, would you willing to include report in the appropriate citation style? Femke Nijsse (talk) 12:30, 7 November 2020 (UTC)

I added the Haines reference to the peer reviewed article section, and modified the <ref> tags in the text that link to it.Dtetta (talk) 17:05, 7 November 2020 (UTC)

You deleted 529,000 number from a review article/secondary source. Sorry, but your personal opinions about what researchers can estimate or not is irrelevant when it comes to published peer-reviewed articles. And that number is actually a mean point estimate, 95% confidence interval is 314 000–736 000. We also can't have just superlatives ("worst health crises in 21st century"), without any quantitative backup, that just reduces the credibility of this Wiki article.Bogazicili (talk) 14:07, 7 November 2020 (UTC)

The WHO number seems to be due to reasons below, this information could be edited, unless you can confirm if its only about malnutrition of children under the age of five.

"The World Health Organization (WHO) estimated that approximately 250,000 deaths annually between 2030 and 2050 could be due to climate change–related increases in heat exposure in elderly people, as well as increases in diarrheal disease, malaria, dengue, coastal flooding, and childhood stunting" [16]

Bogazicili (talk) 14:11, 7 November 2020 (UTC)

I did not delete the number, I just wrote it in a more appropriate form. When there is such an confidence interval, it makes no sense for us to quote the median value to such precision, which is where we commit a crime against significant digits. In contrast to what I implied before, the researchers do not make the claim that they know the number to 3 significant digits. (In contrast to previous discussion we had where the error of the researchers was so bad, that the only conclusion I could draw was that the research was not of sufficiently high quality to be added to this article).

That it's only about the malnutrition of the children under the age of five I got from the 2014 report itself. I wouldn't be surprised if NEJM describe that as childhood stunting. I think however that that is medical jargon, and maybe not even appropriate. The way I'm familiar with that word means that people don't become as tall as they otherwise would have become; not as a cause of mortality. Femke Nijsse (talk) 14:23, 7 November 2020 (UTC)

Lol sorry, I undid my revert. This is because I try to be fast on Wiki and had just done a keyword search (Ctrl + F: 529,000). Yes, I'm fine with current wording or correcting the causes for the number from WHO link. Bogazicili (talk) 14:33, 7 November 2020 (UTC)

Thanks for finding that Haines article, Bogazicili, I think it is excellent. I would still recommend something like: “It is estimated that, by mid century, climate change will be responsible for well over 500,000 additional deaths globally per year due to undernutrition, heat stress, and disease alone” for sentences 4 & 5, and include the WHO report and Haines/NEJM article as the citations for this statement. This characterization of mortality seems to strike a reasonable balance between the need for some context in the extent of the impact, while recognizing that more exact numbers are probably not appropriate. I agree that sentence 6, dealing with other health risks, could be deleted for the sake of brevity.Dtetta (talk) 17:32, 7 November 2020 (UTC) It would be nice to have an article that referenced the original Nature Communications work, as Femke points out. But that seems like something we can flag to work on.Dtetta (talk) 18:29, 7 November 2020 (UTC)

I think that is an excellent compromise now that we have this new 2019 secondary source. I think the source can stand on its own but I don't mind having those WHO report and the original 2016 paper included as well. This solves multiple issues: having too many numbers in the text is ugly prose, it complies with summary style, the contradictory statement is gone, by combining the two numbers we don't overly focus on the RCP 8.5 scenario. Femke Nijsse (talk) 10:15, 8 November 2020 (UTC)

Made that edit, including adding the WHO 2014 report to the references.Dtetta (talk) 17:46, 8 November 2020 (UTC)

Dtetta and Femkemilene, I'm certainly not ok with this edit. WHO says 250k. Newer article says 500k IN ADDITION. So we have 750K predicted deaths total from those two sources, and those sources do not include all climate-change related causes. Whats the rationale for downgrading this to "well over 500,000"? Why not "well over 750,000"? Moreover, this could be considered a misrepresentation of the source. Again, here's the full quote from the article:

The World Health Organization (WHO) estimated that approximately 250,000 deaths annually between 2030 and 2050 could be due to climate change–related increases in heat exposure in elderly people, as well as increases in diarrheal disease, malaria, dengue, coastal flooding, and childhood stunting.16 This is a conservative estimate, because it does not include deaths from other climate-sensitive health outcomes and does not include morbidity or the effects associated with the disruption of health services from extreme weather and climate events. For example, a climate change–associated net increase of 529,000 adult deaths worldwide (95% confidence interval [CI], 314,000 to 736,000) was projected to result from expected reductions in food availability (particularly fruit and vegetables) by 2050, as compared with a reference scenario without climate change.23

Below is what I had added, which made it clear WHO number and reductions in food availability number were mutually exclusive, and they were also not exhaustive:

The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year, from malnutrition, malaria, diarrhea and heat stress.[177][176] This is a conservative estimate, as it does not include deaths due to other related reasons. For example, additional 529,000 adult deaths are predicted worldwide by 2050, due to expected reductions in food availability.[176]

I'm kinda ok with changing 529,000 to half million (and actually I'm not even sure about that now, since it caused lots of confusion. I'm thinking maybe Dtetta did not see we had "half a million" in the text in addition to WHO number?), and ok with fixing the causes for WHO source. But I am not ok with the downward revision and merging the two numbers that Dtetta did. If you want the wiki-specific term, this is against Wikipedia:No_original_research#Synthesis_of_published_material, since you merged 250,000 deaths and 529,000 adult deaths as "well over 500,000." Bogazicili (talk) 19:21, 8 November 2020 (UTC)

Actually here's my full suggestion, I fixed the WHO causes (Figure 1.1, page 4 [17]; also correctly summarized here [18])

The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year due to heat exposure in elderly people, increases in diarrheal disease, malaria, dengue, coastal flooding, and childhood stunting.[177][176] This is a conservative estimate, as it does not include deaths due to other related reasons. For example, additional 529,000 adult deaths (95% confidence interval, 314,000 to 736,000) are predicted worldwide by 2050, due to expected reductions in food availability.[176]

Since I noticed a lot of second guessing of numbers published by reliable sources (ie: peer-reviewed journals), I included the full 95% confidence interval range. Bogazicili (talk) 19:49, 8 November 2020 (UTC)

summarising numerical information is not originally research, although it is fair to argue how it is best done. I think a more conservative summary is appropriate because we know the number of adults deaths comes from the unrealistic RCP 8.5 scenario.

I'm against anything that mentions more than one number for prose reasons and brevity. Your new proposal is to wordy as well. I didn't think it complies with the well written criterion features article because of this. You reintroduced a grammar error well (..an.. additional), as well as unnecessary repetition (having both predicted and expected in one sentence). We don't use the word predict in climate science; we usually use project. Saying that something is a conservative estimate is a waste of words is the second part of the sentence already indicates these are two separate issues. In short: this proposal ignores any of the small improvements I made. Femke Nijsse (talk) 20:01, 8 November 2020 (UTC)

Obviously not suggesting adding grammatical errors.

I used the RCP 8.5 number, because that is the number the secondary source uses. Projected number for RCP 4.5 is still 368,000 for the middle of the road scenario in the original article. They didn't give a CI for that but 500k would probably be within it.

If conservative is too redundant, there will still need to be something additional saying that numbers given are not exhaustive. Adding "alone" at the end is insufficient. And again, current version misrepresents the sources, which is a much bigger issue than grammar:

"It is estimated that, by mid century, climate change will be responsible for well over 500,000 additional deaths globally per year due to undernutrition, heat stress, and disease alone"

Are you claiming all diseases consist of "diarrheal disease, malaria and dengue"? Bogazicili (talk) 20:34, 8 November 2020 (UTC)

Maybe we could break out the WHO 2050 numbers for heat and disease, and describe the Lancet/Haines 2050 numbers for undernutrition separately. I can take a shot at doing that if that makes sense. It might also makes sense to mention that some of these estimates (particularly flood mortality) could vary significantly depending on the success of adaptation measures, as the WHO report mentions. The Lancet/Haines estimate does comes from a higher temperature scenario, but as I mentioned earlier, 1)the various temperature scenarios don’t deviate that much in 2050 (the differences become more pronounced after that) and 2) the authors go into a fair amount of detail looking at all of their assumptions, and come to the conclusion that, if anything, their numbers are more likely an underestimate.Dtetta (talk) 20:30, 8 November 2020 (UTC)

They were already separated before your edits, are you suggesting returning to that or a different version? They will definitely need to be separated, you can't merge them and round up to the nearest .5 million (and wrong .5 million by the way). It doesn't matter if Lancet estimate comes from a higher temperature scenario. That is the number used in a secondary source. Bogazicili (talk) 20:43, 8 November 2020 (UTC)

I’m talking about using the 2050 heat mortality(~100,000) and disease mortality(~60,000) numbers from WHO, and separately mentioning the undernutrition mortality number(~500,000) from Lancet/Haines.Dtetta (talk) 22:58, 8 November 2020 (UTC)

There is no "disease mortality". WHO source looked at only "diarrheal disease, malaria and dengue". You can't claim that's ALL of the climate change influenced disease mortality for ALL DISEASES. There's also no "heat mortality". WHO source looked at only heat exposure in elderly people. I'm pretty sure non-elderly people are not 100% immune to this. And why are you breaking down the 250k number from WHO source? On what basis? I'll have to undo your latest edit, as it misrepresents the source per my answer to Femkemilene; it's not appropriate for a FA class article. Bogazicili (talk) 18:27, 9 November 2020 (UTC)

Here's my updated suggestion, which is basically the version after Femkemilene's edit, with 3 changes:

1) corrected causes for 250k WHO number 2) added "further" instead of "additional" 3) added 529,000 instead of half million

The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year, from heat exposure in elderly people, increases in diarrheal disease, malaria, dengue, coastal flooding, and childhood stunting.[176] [177] A further 529,000 adult deaths are projected yearly by 2050, due to reductions in food availability and quality.[178] Other major health risks associated with climate change include air and water quality, and social factors.[179] The WHO has classified human health impacts from climate change as the greatest threat to global health in the 21st century.[11]

First and second changes are self-explanatory. Third change is because I think we should stick to the exact numbers the sources use. I also think this is more sustainable. If new editors come down the road and question the half a million number, I don't want to go through lengthy and time-consuming discussions again (about that 3 significant numbers were too much and we settled on half a million number). We can also add the confidence interval or make a footnote for it if required. Bogazicili (talk) 18:44, 9 November 2020 (UTC)

Bogazicili I just reverted your edit, because 1)you did not propose language here first and wait for a response from other editors such as Femkemilene or me, 2)your reversion incorrectly cited the NEJM study in support of your sentence on WHO estimates, and 3)I believe you are double counting the malnutrition/undernutrition mortality estimates when you say “an additional half million adult deaths”. Since this is a significant issue on this page, I think we should take the time to get it right. The language I used is factually correct; I believe yours is not. I’m fine with language other than what I proposed, if other editors believe there should be something different. But I proposed language here first, and it was given a positive review by another editor (in this case Femke), before I posted it. Let’s see if there are any positive comments on what you are proposing here before you actually make these changes.Dtetta (talk) 02:14, 10 November 2020 (UTC)

Page 2 of the Lancet report specifically discusses the WHO analysis and relates their estimates to WHO’s in a manner that indicates that their mortality estimates differ from WHO’s for a few different reasons, but that both studies were attempts to quantify the same kind of CC effect, and that it’s not appropriate to present these two estimates in an additive fashion.Dtetta (talk) 03:30, 10 November 2020 (UTC)

A kind reminder that we do not wish to end up in an edit war. Use the revert button conservatively.

I think the correct interpretation is closer to Bogazicili's than Dtetta. The NEJM study contains the WHO estimates, so should be a proper citation. The Lancet study indicates (on page 2) there is large complementarity between the two studies. The WHO focuses on childhood malnutrition, whereas the Lancet study only includes adults. Because the studies are not done in exactly the same framework, there is a chance of double counting. For instance, a child dying in the WHO study dying again in the Lancet study. The two studies also report on different periods, making the comparison more difficult. I propose the following:

• a sentence citing the half million that only refers to the adult mortality of the Lancet study due to food quality and quantity.
• A further sentence without numbers enumerating additional causes of mortality as a consequence of climate change.

This should solve the discussion about content, and the poor prose issues of having to many numbers (both years and numbers of deaths), and the issue of brevity. (Femkemilene on a wiki break; logged out).

I think that is a good suggestion.Dtetta (talk) 15:09, 10 November 2020 (UTC)

Dtetta,

1) I had reverted to Femkemilene's version, not mine.

2) WHO and Lancet report looked at DIFFERENT CAUSES, so there is no overlap. WHO looked at child undernutrition. Lancet looked at adult undernutrition.

3) Even if there is an overlap, these are your speculations at the moment. It is not the job of Wikipedia editors to speculate in this manner. Find reliable sources that say there is an overlap. Until then, we stick to the secondary source (NEJM), which uses BOTH 250K and 529K numbers SEPARATELY. Even if there is an overlap, it might also be negligible.

4) Also brevity is not an appropriate argument here, as this is one of the most important paragraphs in the article. If you want brevity, shorten UNFCCC section. We do not need 2 big paragraphs for expired treaties, when we have a currently-active Paris agreement paragraph.

5) I'm willing to go to RFC or mediation for this (if we can't get enough 3rd opinions). Until then the article should be reverted to last stable version (edited by Femkemilene). I'll wait for Femkemilene to finalize their proposal, so I can add both that and my most recent one as part of RFC. Bogazicili (talk) 19:20, 10 November 2020 (UTC)

Bogazicili - at this moment I would suggest we defer to Femkemilene (a skilled and experienced editor), on this, and let her attempt to craft what she thinks is appropriate language, before you escalate the issue. I believe Page 2 of the Lancet report, in which the authors compare their work with WHO's, provides the best guide for how to characterize the various mortality estimates, if it's decided that more detail is needed for the sentence(s) in question. I also think the Lancet study should be included with the NEJM and WHO reports as part of the citations for the sentence, as Page 2 of that report provides a more focused background for the reader who wants to follow this aspect in more detail (compared to the NEJM reference).Dtetta (talk) 21:29, 10 November 2020 (UTC)

Dtetta, I read page 2 of Lancet report. It specifically says it is complementary to WHO report (under "Implications of all the available evidence" section). That suggests there is no overlap. In math, a complement of a set is anything not in that set (Complement (set theory)). So I really have no idea what the basis of your argument is.

I would have loved to defer to skilled and experienced editors on this topic. I do not consider this a form of leisure, especially these excessive discussions. But when I came to the article, I found several things downplayed.

People usually stick to their opinions after length discussions, so I'll give a week for everyone to cool, and then we can talk again. But I intend to escalate after that since I see no reason why those 2 numbers shouldn't be in the article.Bogazicili (talk) 15:18, 12 November 2020 (UTC)

Bogazicili I am not saying those two numbers shouldn’t be in the article; I am concerned about the sentence expressing the Lancet estimate as additional deaths. Another approach you might consider is to contact one of the authors of the Lancet article via email, and get their thoughts on how the two reports should be collectively characterized. Nowhere on page 2 do they mention that what they are presenting is mortality that’s in addition to the WHO nutrition related mortality estimates. They talk about how their estimates are much larger than the WHO estimates and other ways that the two are related. So I think there is a lack of clarity on this particular point. I’ve contacted researchers in the past, identified myself as a Wikipedia editor, and found that researchers are often more than happy to help describe how they view their research results. That would be useful information for our group to know. Dtetta (talk) 16:22, 12 November 2020 (UTC)

Complementarity in science means something slightly different than in mathematics. It means there is very little overlap, not necessarily none. You could indeed ask the authors whether they think there is none. I still believe we shouldn't commit any crimes against significant digits, nor include to many numbers to maintain readability. I have removed childhood stunting, because it feels like jargon to me, and I don't think it is necessary to repeat other causes as they are ready mention above.

It is estimated that reduced food quality and quantity will be responsible for around half a million adult deaths per year by mid-century. (cite NEJM & Lancet). Climate change drives additional mortality via heat exposure in elderly people, diarrheal disease, and increased risk of coastal flooding. (cite NEJM and WHO).

P.S. Dtetta, I notice that you're not quite following the (overly complicated) citation style. The short cites should cite authors, not the publisher. For some publications those two approximately coincide (for instance the WHO). Femke Nijsse (talk) 20:05, 12 November 2020 (UTC)

Understand your comment on citations. Will make that adjustment in future edits. Also suggest you consider describing the disease and heat exposure risk with rough numbers, as they are included in the WHO/Nature Communications sources. I think it’s also worth briefly mentioning that (as I believe the WHO states) future mortality may vary significantly depending on adaptation measures, which may prompt the reader to continue to the adaptation section. But your call on these aspects. Dtetta (talk) 03:56, 13 November 2020 (UTC)

All these effects depend strongly on adaptation measures, and I wouldn't be against a reshuffling of the article to bring effects and adapation into one section (similar to IPCC), and have mitigation as a section on its own (with geo-engineering losing its section heading, which feels undue to me). I'm open to adding a sentence of that kind into the article as an intermediate solution. Could you propose it? Trying to dial down a bit on Wikipedia with new job draining my mental juice.

I think mentioning too many numbers would be against FA criterion 1a: its prose is engaging and of a professional standard. I'm okay to include these numbers in the footnote. Femke Nijsse (talk) 16:44, 14 November 2020 (UTC)

Yes I can do that. I think I will try to contact one of the Lancet editors first, just to get their opinion on this, unless Bogazicili posts here that he is already planning on contacting them. Once I hear back I’ll post revised proposed language here based on what you have presented, but add a short statement on adaptation effects on mortality, as well as footnotes that include the heat and disease mortality numbers from WHO/Nature Comm. Dtetta (talk) 05:21, 15 November 2020 (UTC)

Nope, please go ahead. I was going to suggest Femkemilene to do it. IMO, the onus is on you two, since you two are the ones speculating. Both numbers were used in the secondary source. I am the one suggesting following the secondary source. Also, I don't think 2 numbers in paragraph is too many. After you have your response, I'll open the RfC, I don't think anyone is going to change their opinion. We need other opinions. Bogazicili (talk) 18:43, 15 November 2020 (UTC)

References

Climate Security

We need two sentences here. Military experts are experts on security, so opinions of US military, NATO [19] etc are relevant. One sentence for that, and another from scientific or other sources such as UN [20] Bogazicili (talk) 01:15, 12 October 2020 (UTC)

the opinions of individual military experts are not relevant for this top-level article, even if they are a NATO general. If the NATO as an organisation would say something like that, I would be willing to reconsider, but my guess is that that is still more appropriate for an article such as effects of climate change. The UN piece seems to be an opinion piece, from two PIK scientists who are known for holding a slightly more extreme view than the average climate scientist. We should use review pieces that are peer reviewed for these kind of claims, as its very difficult scientific question. Femke Nijsse (talk) 08:39, 12 October 2020 (UTC)

I'll return to this later. Bogazicili (talk) 03:57, 22 October 2020 (UTC)

I think climate security issues are best dealt with as a modification to the adaptation section (which could use some general strengthening), and it would make sense to include some of the concepts in Bogazicili’s Footnote 1 in that modification, even if that specific article is not used. Whether we use DoD/millitary assessments or other sources doesn’t matter that much to me. I don’t think the idea of referencing a DoD assessment is necessarily biased; my recollection is that some of the Pentagon reports are looking at the risk of climate change from a global perspective. They may be particularly concerned about its impact on US security, but I think the risks they’re talking about are often global in nature. I don’t think the question of how much emissions are from the US military is all that relevant to this issue, I say we focus on the merits of the ideas mentioned in Footnote 1.Dtetta (talk) 22:10, 24 October 2020 (UTC)

I'd also like to say that adding views of CIA, NATO, Pentagon etc means adding more diverse viewpoints (ie: from security experts), especially given that some people easily dismiss viewpoints of scientists. See: Climate change denial. Bogazicili (talk) 04:01, 25 October 2020 (UTC)

IPCC Too Conservative

Femkemilene said "Saying that scientists have underestimated impacts may be true, but the source is from 2013." I have found later sources such as [21], ""The IPCC tends to be very cautious and conservative, which is why it had to correct itself upwards already several times," Rahmstorf said." [22] Again needs better sources. Bogazicili (talk) 01:15, 12 October 2020 (UTC)

I'll wait for you to collect better sourcing, but I would be surprised if you can convince me this is WP:DUE. Femke Nijsse (talk) 17:31, 13 October 2020 (UTC)

"However, the available evidence suggests that scientists have in fact been conservative in their projections of the impacts of climate change. In particular, we discuss recent studies showing that at least some of the key attributes of global warming from increased atmospheric greenhouse gases have been under-predicted, particularly in IPCC assessments of the physical science, by Working Group I" [23]. This is a highly cited paper, 271 citations [24].

Secondary source:

"However, some climate science experts regard the IPCC’s data as too conservative. Some note the potential impact of self-reinforcing feedback loops, or tipping points, such as the loss of reflective white sea ice allowing the ocean to absorb more heat, 7 or the potential release of large amounts of methane – a much more potent greenhouse gas than CO2 – from melting surface permafrost on land 8 and the Arctic seabed." [25]

I've provided multiple studies, newspaper articles (with quotes from scientists), and a secondary source. I don't think it's UNDUE. Bogazicili (talk) 03:56, 22 October 2020 (UTC)

Currently, the article states: The physical realism of models is tested by examining their ability to simulate contemporary or past climates. Past models have underestimated the rate of Arctic shrinkage and underestimated the rate of precipitation increase. Sea level rise since 1990 was underestimated in older models, but now agrees well with observations. The 2017 United States-published National Climate Assessment notes that "climate models may still be underestimating or missing relevant feedback processes".. So the physical aspects are well covered already in the article.

Criticism of the IPCC specifically feels out of place to me, as were citing a broader scope of literature. For instance, for sea level we cite not only the IPCC, but also study which finds more sea level rise. We are ready talk about self reinforcing feedbacks and tipping points.. I feel the article will start to feel biased if we were to emphasise models underestimating more. There also aspects where models have overestimated effects, such as the high climate sensitivity in the latest generation of models. Femke Nijsse (talk) 20:25, 28 October 2020 (UTC)

It's not covered in humans section though. We need something short saying that there might have been an underestimate in this area as well. Your quotes from rest of the article show there is a reasonable case why there might have been underestimates in terms of human impacts of climate change. A lot of the things discussed in this subsection is also older than the latest generation of models. I also see you are the lead author of the article you quoted that was recently published, congrats! Bogazicili (talk) 00:32, 29 October 2020 (UTC)

For the human impacts their are also reasons why results are sometimes overstated instead of understated. The main point is that social scientists have often misinterpreted the RCP 8.5 scenario, interpreting it as a business as usual scenario, instead of a worst-case scenario. The sources you provide so far are not convincing that there is a systematic understatement of results for the social impacts. Convincing literature is high quality secondary literature that reviews high quality peer-reviewed primary research. It is a very strong statement, and therefore requires extraordinary evidence. Femke Nijsse (talk) 08:25, 30 October 2020 (UTC)

Some of the highly cited papers I quoted is quite recent (eg: 2018, 2019). The review studies will be coming out in 2025 or something. Also some of the overestimates may not matter in the overall conclusion. Eg:

"we find that a majority of models underestimate the extremeness of impacts in important sectors such as agriculture, terrestrial ecosystems, and heat-related human mortality, while impacts on water resources and hydropower are overestimated in some river basins; and the spread across models is often large. This has important implications for economic assessments of climate change impacts that rely on these models. It also means that societal risks from future extreme events may be greater than previously thought." 2019 study

"We show how to account for this second source of uncertainty in a physically well-founded and tractable way, and we demonstrate that even modest variability implies trillions of dollars of previously unaccounted for economic damages" October 2020

Perhaps, instead of referencing IPCC, we can just say many effects of climate change with respect to humans (health, economy etc) have been underestimated. Bogazicili (talk) 08:41, 30 October 2020 (UTC)

You cited the same study twice per accident (the one specific to Europe, and specific to extreme events). Is the other one more general? The next IPCC report is only 9 months away, so I'd say we wait for that. Femke Nijsse (talk) 09:16, 30 October 2020 (UTC)

This is the October 2020 study [26]

Also, I had already cited a secondary source before that said economic effects were underestimated.

"Economic assessments of the potential future risks of climate change have been omitting or grossly underestimating many of the most serious consequences for lives and livelihoods because these risks are difficult to quantify precisely and lie outside of human experience" [27] Bogazicili (talk) 17:29, 5 November 2020 (UTC)

We have already added text to the economics section, and your previous comments seem to suggest that you want to and general comments about that human impacts have been underestimated. You have not provided any general source, and I doubt you will find one which has broad support from the scientific community.

While I like criticising current integrated assessment modelling, I don't see a way to include that 2020 study into our article. It is criticising information that we don't even include in our article because it is too detailed. The article is my opinion probably even too specialised for a sub article: effects of climate change. Femke Nijsse (talk) 17:08, 6 November 2020 (UTC)

I wasn't suggesting adding that into the article, I was just citing recent articles for the purposes of this discussion.

I'll add that economic impacts have been underestimated into the article (per the source I just cited and the IMF paper, both of which are secondary sources).

I will come back to this once I find more secondary sources for the more general statement that I thought was missing and/or once the new IPCC comes out. I think this is an important topic, since some people assume a lot of the potential impacts predicted are alarmist. On the contrary, some have been underestimated. Bogazicili (talk) 11:31, 7 November 2020 (UTC)

I can live with the addition that economic impacts have been underestimated for now. I do worry about that were using WP: Wikivoice where we shouldn't. Are we sure most economists believe that economic impacts have been underestimated? If others want to revert, I'm okay with that as well. Femke Nijsse (talk) 12:03, 7 November 2020 (UTC)

This is what IMF paper says:

"The climate risks in central banks’ collateral frameworks and asset portfolios could be more adequately assessed and reflected. As discussed above, financial markets, including credit rating agencies, tend to underestimate climate risk, generating biases in capital allocation toward carbon-intensive activities."

"Financial markets" is very broad, and justifies the current wording I think, especially combined with the source from 3 institutes previously cited. Bogazicili (talk) 12:23, 7 November 2020 (UTC)

References

1.2 billion displaced

The following sentence was added to the article: A recent report put the number of people at risk of displacement by 2050 at 1.2 billion.. There are multiple problems with the sentence, and I'm not sure that the sourcing is sufficiently good. Most importantly, the current formulation gives the impression that the displacement is caused by climate change, instead of a very wide selection of ecological threats. Less importantly, we should avoid the word recent in this article (WP:RELTIME). I'm not that familiar with the think tank, but I'm always sceptical of them. A further concern is that there is cherry picking by only quoting high numbers of people at risk of displacement, without indicating that confidence is low in a certain direction. Femke Nijsse (talk) 07:19, 8 October 2020 (UTC)

That's fine, I only added that since you insisted on a newer source. Bogazicili (talk) 03:38, 22 October 2020 (UTC)

References

"Manufactured" and "unwarranted" doubt

“ Like the tobacco industry before, the main strategy of these groups has been to manufacture doubt about scientific data and results. Many who deny, dismiss, or hold unwarranted doubt... ” — Section 7.3 "The public. Denial and misinformation"

How can doubt be "manufactured" or "unwarranted"? Doubt is always possible and it's always "warranted", if we are commited to critical thinking. What really can be manufactured is perception that there is no prevalent view among scientists (which is a false perception), and what really can be unwarranted is the opinion that there is no prevalent view among scientists (this opinion has no basis in reality).

Moreover, the tobacco industry exploited a really existing uncertainty to its own advantage. After the relevant evidence had accumulated and uncertainty had been largely cleared, it ceased to claim anything along the lines of "the harm of smoking is unproven" etc. The whole point of the concept of "climate change denialism" is that the people holding the views encompassed by the concept reject the scientific consesnsus and do not exploit any controversy.

109.252.202.95 (talk) 13:17, 11 October 2020 (UTC)

Manufactured doubt: That's not how reliable sources see it.

Tobacco industry: That's not how reliable sources see it.

You should read the related article Climate change denial. It will tell you how manufacturing unwarranted doubt works. Denialism may help too. --Hob Gadling (talk) 14:03, 11 October 2020 (UTC)

You don't need "reliable sources" to understand and appreciate the first point. As regards tobacco industry, you can't deny that tobacco industry already acknowledges firmly established health risks from smoking. No article can tell "how manufacturing unwarranted doubt works", because there is no such thing at all. Doubt is always warranted and always natural, you don't need to manufacture it. Doubt is also the driver of science. Doubt differentiates science from pseudoscience.

109.252.202.95 (talk) 03:10, 25 October 2020 (UTC)

Rewriting first paragraph of "Mitigation / Technologies and other methods"

Current paragraph is this:

Key factors to reducing greenhouse gas emissions in all long-term scenarios include rapid and significant investment in renewable energy, nuclear energy, and energy efficiency. Renewable energy technologies include solar and wind power, bioenergy, geothermal energy, and hydropower. Photovoltaic solar and wind, in particular, have seen substantial growth and progress over the last few years, such that they are currently among the cheapest sources of new power generation. Renewables represented 75% of all new electricity generation installed in 2019, with solar and wind constituting nearly all of that amount. However, fossil fuels continue to dominate world energy supplies. In 2018, fossil fuels produced 80% of the world's energy, with modern renewable sources, including solar and wind power, accounting for around 11%.

Suggested rewrite is this:

Fossil fuels accounted for 80% of the world's energy in 2018, while the remaining share of power production was split between nuclear power, hydropower, and non-hydro renewables. Nuclear power has seen costs increasing amid stagnant power share, raising questions about its future prospects. Hydropower will continue to grow slowly due to efficiency gains, but expansion is difficult as there are few remaining places to build dams that are environmentally, economically and socially acceptable. Non-hydro renewable energy technologies include solar and wind power, bioenergy, and geothermal energy. Photovoltaic solar and wind, in particular, have seen substantial growth and progress over the last few years, such that they are currently among the cheapest sources of new power generation. Renewables represented 75% of all new electricity generation installed in 2019, with solar and wind constituting nearly all of that amount.

Reasoning: I believe the section benefits from breaking down the current power mix, and in particular spelling out the prospects for nuclear and hydro. Nuclear equals non-hydro renewable power production, and hydro currently leads both nuclear and non-hydro renewables by quite a bit. Nuclear needs to be mentioned to say why it is not a focus of the rest of the section. Hydro needs to be broken out because too often it is grouped with renewables for the purpose of talking about power share (where it dominates the power mix), then ungrouped when talking about future prospects (where there is not much growth prospect, plus major environmental concerns). There's also some verbiage and puffery in the current wording that can be squeezed out (what is a "modern renewable"?). I think the rewrite better grounds the introduction, to justify why the remainder is focused on non-hydro renewables (other than bias). Efbrazil (talk) 18:50, 11 October 2020 (UTC)

I think the text you provide is okay, but the sourcing is poor where you changed it. Let's stick to high quality reliable sources, and most importantly sources about climate change or climate change mitigation. The risk to give undue attention to certain aspects of related topics is quite big when editors use the literature about that related topic instead of about the main topic. Verification failed for the nuclear source. If you cite the report (instead of the webpage to the report, what you seem to be doing now) you should cite a page number. The term modern renewable is jargon (it might seem puffery if you're not familiar with the jargon), so I agree it can be removed. Femke Nijsse (talk) 19:13, 11 October 2020 (UTC)

I'll update the references as best I can and put the new text in the article. I chose sources as the best places to go if you wanted to learn more about the topic, such as the future of nuclear power, rather than sources needed to justify pretty basic statements of fact. If you are looking at the future of nuclear power it is better to read the best source about nuclear power rather than to find some general statement on climate change. You're right I should add page numbers and I'll also add quotes like I did in the intro for the "effects" paragraph. I think quotes are as important as page numbers, as they make the source much more accessible to the reader and discourage edits that will disconnect the content from the source. Efbrazil (talk) 17:08, 12 October 2020 (UTC)

Done, but I could use your help with the World Nuclear Status Report. It appears to be the main source all the news articles use for talking about nuclear power, but I can't find an ISBN or other info to make it more like a "real" source. It's an annual report with an author, but that's not a reference type. Maybe we just switch over to a reputable secondary source that uses it, like reuters here: https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J ? I switched hydro sourcing over to the IEA. The quotes aren't as good, but source is more obviously credible. The sources that were originally used are all still there. Efbrazil (talk) 19:58, 12 October 2020 (UTC)

Hoped I would have a little more time to comment, but here are my first impressions/thoughts. Although I appreciate your interest in minimizing redundancy and attempting to characterize the power mix more completely, I think this paragraph has serious flaws.

• It lacks focus. What is your basic message for this paragraph? That should be captured in the first sentence.
• The sentences about nuclear and hydro read like opinions, and are followed by a generic list of renewable energy technologies. This is a serious disconnect in the tone of the paragraph.

As there seems to be a strong interest in rewriting this paragraph now, I would suggest the following thoughts for the framework of the intro paragraph, which I think is trying to set the backdrop for an overview of the principle mitigation technologies/techniques in the rest of the subsection:

• Since 90% of GHG emissions come from the use of fossil fuels, expanding renewable energy and decarbonizing the transportation and heating sectors are the most likely paths for limiting energy related GHG emissions.
• The current installed power mix is largely fossil fuels, but new investment is dominated by renewable energy, particularly wind and solar, as these are now among the most cost effective energy production technologies.
• Fossil fuels have particular dominance in the heating and transportation sectors, and most of the inroads made by renewable energy to date have been in the electricity sector. That is envisioned to change significantly over the next 30 years. (We should probably also have a brief mention of decarbonizing technologies in this subsection).
• Although they play a significant role in today’s power mix, for a variety of reasons, nuclear energy and hydro power are unlikely to see expansion globally as countries carry out their mitigation efforts.

I will propose a revised paragraph based on these ideas....let me know if you think there are any other important concepts that should be included, or if any of these ideas should not be part of the intro paragraph.

I think first sentence of the second paragraph also needs to be redone, but that can be addressed later. Dtetta (talk) 21:34, 12 October 2020 (UTC)

The message of the paragraph is "this is how power sourcing is now, and this is the direction it is moving in". We shouldn't just lead with renewables, because they remain a tiny fraction of the overall grid, and leading with them comes across as bias.

Efbrazil - I don’t think you are recognizing and adequately addressing the concerns and suggestions that Femke and I have expressed. Maybe the earlier version of this paragraph had problems (I think the first sentence could be better written), but they are not as significant as you make them out to be, and I think your edits are a step backwards for a lead-in paragraph, given the rest of the text in the subsection. In addition, I don’t think you have responded at all to my suggestions for the general framework of the paragraph, and I don’t think what you’ve written it is consistent with what you are claiming as your stated message. Your paragraph probably would reflect your stated message if you eliminated the sentences on nuclear and hydro, but you seem clearly opposed to doing that, and those sentences greatly shape the overall flow of thoughts in the paragraph. If you are truly striving for a NPOV, why isn’t a one sentence assessment of biomass/bioenergy included here? Or geothermal, which is significant in some countries? Both are part of the figure you reference.Dtetta (talk) 00:18, 15 October 2020 (UTC)

I just updated the references above to the ones I put in the article. A key point that we need to address is the nuclear vs renewable debate, as that's where a lot of discussions happen. We previously just ignored nuclear. I attempted to address the issue stating the reason for the lack of progress in nuclear, then putting a quote in the references that has the numbers to make it not come across as "an opinion". I agree it would be better if we had a paragraph on nuclear so the statement came across less as an opinion. I recommend you read this article as well, the last half of the article really breaks things down well in terms of numbers, and I'm hoping we can ground the discussion more with number like this: https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J Efbrazil (talk) 00:56, 13 October 2020 (UTC)

Nuclear vs renewable may be a debate topic in some circles, but that does not mean it needs to be covered in this paragraph. I think the nuclear and hydropower sentences should be eliminated from the intro paragraph and placed somewhere else in the subsection. That would be a better way of addressing your NPOV concerns.Dtetta (talk) 00:18, 15 October 2020 (UTC)

While we are writing the new version, shall we go back to the old version? The two new sentences are not supported by the sources. Furthermore, the sources don't make clear that this information is due, because specialist literature is used instead of climate change literature. Per WP:SCIRS: Cite reviews, don't write them. I think using reviews is very important in this case as we have a discussion about the relative importance of different topics in these paragraphs. Review sources are the easiest way to solve these questions, and we're lucky to have plenty of high quality reviews.

I agree with Dtetta that there is a mix match between how nuclear and hydro are described compared to the power sources that are projected to play the main role in decarbonisation. I think having expert assessment language is fine (the nuclear sentence if sourcing is fixed), but the sentence for hydropower is too long and more certain than the sources it cites. We should not have an entire paragraph dedicated to nuclear, that will be undue. I'm happy for Dtetta to propose a revised paragraph based on the ideas described above, and based on various review sources. Femke Nijsse (talk) 17:11, 13 October 2020 (UTC)

The original paragraph is really a mess, so I oppose going backwards. The original paragraph says key factors are nuclear, energy efficiency, and renewables, then ignores nuclear and puts all the focus on renewables without explaining why. It comes across as pure bias. I updated the sourcing on the new content, hopefully that works for you? Efbrazil (talk) 21:55, 13 October 2020 (UTC)

I disagree that the current paragraph is a mess, as I explained above. This is starting to seem like a dispute resolution situation, which is very unfortunate given that this article is going to be in FAR review.Dtetta (talk) 00:18, 15 October 2020 (UTC)

Template:U:dtetta: I'd like to see us move forward on a converged language. I included Femke's suggestions on sourcing so I think that issue is addressed, and we are in agreement on the wording in general. Can you suggest wording that addresses your concerns, or just make edits to the content if there's a minor change you want? Efbrazil (talk) 20:17, 15 October 2020 (UTC)

Sure - I will work on a proposed revision based on the framework I described above and post it here this weekend.Dtetta (talk) 18:58, 16 October 2020 (UTC)

After thinking about other ways of rewriting the sentence, I think we should just go with the October 6 version of this paragraph, as Femke suggeated, although we could substitute my original sentence from May: “Long-term scenarios all point to rapid and significant investment in renewable energy and energy efficiency as key to reducing GHG emissions”, for the October 6 lead sentence. We could keep your edit that eliminates the sentence that discussed how much power renewables are capable of providing, although I think that strengthens the point being made, and I don’t see this as necessarily a nuclear vs renewables debate. The mention of nuclear energy in the October 6 first sentence should be eliminated, as it was not in the UNEP report citation that is being used. Not sure how it ended up being there.

The first sentence (and main message of the paragraph) are from page 46 of the same UNEP report that you cite...and I think its one of the best ways of introducing the technologies that are being covered in the rest of this subsection. I think it’s stronger and more focused than the general power mix lead-in that you’ve written in your 10/12 edit. I don’t think it’s biased, in that it is simply paraphrasing the UNEP report, and the paragraph already clearly stated how fossil fuels currently dominate the power mix.

We could add your sentences about hydropower and nuclear power, with minor modifications, at the end of the second paragraph in that subsection, which involves a more specific assessment of the relative merits of the various RE technologies. I think they would be less out of place there.

Hope to get thoughts from others on this. Femke? Dtetta (talk) 05:27, 18 October 2020 (UTC)

I think Efbrazil is right hydro and nuclear should be mentioned, and they fit perfectly in the second paragraph. I hope you can use our overview sources we have, as news articles aren't appropriate for scientific facts (Reuters). I'm okay with going back to the October 6 paragraph with the failed verification fixed. I think the paragraph on how much energy renewable sources can provide isn't biased, but it is a slight repetition of sentences in the decarbonisation pathways section, which already indicates that renewable sources can provide almost hundred percent of energy needs, so for brevity I think it should be left out. Femke Nijsse (talk) 08:04, 18 October 2020 (UTC)

Efbrazil - what do you think of this as compromise language?

Long-term scenarios point to rapid and significant investment in renewable energy and energy efficiency as key to reducing GHG emissions. Fossil fuels accounted for 80% of the world's energy in 2018, while the remaining share of power production was split between nuclear power, hydropower, and non-hydro renewables.; that mix is expected to change significantly over the next 30 years. Renewable energy technologies include solar and wind power, bioenergy, geothermal energy, and hydropower. Photovoltaic solar and wind, in particular, have seen substantial growth and progress over the last few years, such that they are currently among the cheapest sources of new power generation. Renewables represented 75% of all new electricity generation installed in 2019, with solar and wind constituting nearly all of that amount.

The second paragraph of the currently tItled “Technologies and other methods” section would then read something like:

There are obstacles to the continued rapid development of renewable energy. Environmental and land use concerns are sometimes associated with large solar, wind and hydropower projects. Solar and wind power also require energy storage systems and other modifications to the electricity grid to operate effectively, although several storage technologies are now emerging to supplement the traditional use of pumped-storage hydropower. The use of rare-earth metals and other hazardous materials has also been raised as a concern with solar power. The use of bioenergy is often not carbon neutral, and may have negative consequences for food security, largely due to the amount of land required compared to other renewable energy options. Hydropower growth has been slowing and is set to decline further due to concerns about social and environmental impacts. While not a traditional renewable, nuclear energy has continued to be a significant part of the global energy mix. However, nuclear power has seen costs increasing amid stagnant power share, so that nuclear power generation is now several times more expensive per megawatt hour than wind and solar.

Dtetta (talk) 14:30, 18 October 2020 (UTC)

Dtetta Sorry for disappearing, life got in the way of my highly paid job as a wikipedia editor. I'm fine with the above language, thanks for rolling it out. I'm still not fine with the section title "Technology and other methods", which to me means nothing at all. I split the title up into 2: "Changing sources of energy", and "Carbon capture and sequestration". I hope that's OK? I'm fine with further edits to the section titles, but I really hate "Technology and other methods" for reasons I've gone into ad nauseum up above. Efbrazil (talk) 14:32, 11 November 2020 (UTC)

References

I wanted to make a change in a similar direction. Seems like improvement. Femke Nijsse (talk) 14:56, 11 November 2020 (UTC)

Efbrazil I think that is a good way to break it up, and the titles are now more clearly connected to the text. Thanks for doing that. Dtetta (talk) 15:37, 11 November 2020 (UTC)

Hysteresis of the Antarctic Ice Sheet

See here:

"...at global warming levels around 2 degrees Celsius above pre-industrial levels, West Antarctica is committed to long-term partial collapse owing to the marine ice-sheet instability."

"...the West Antarctic Ice Sheet does not regrow to its modern extent until temperatures are at least one degree Celsius lower than pre-industrial levels. Our results show that if the Paris Agreement is not met, Antarctica’s long-term sea-level contribution will dramatically increase and exceed that of all other sources." Count Iblis (talk) 02:04, 29 October 2020 (UTC)

that is bad news, those authors are solid. I'm reluctant to include this specific information in this article as its primary source. It definitely needs adding to sea level rise. Our article currently says "An example [red, of a tipping point] is the collapse of West Antarctic and Greenland ice sheets, where a certain temperature rise commits an ice sheet to melt, although the time scale required is uncertain and depends on future warming". In the estimates of sea level rise, some Antarctic contribution is already taken into account, but these estimates may be a bit low. In April next year I believe the next IPCC report is due to be published, which should have an assessment of the article you cited above. Do you propose specific changes? Femke Nijsse (talk) 08:10, 29 October 2020 (UTC)

Today's coverage in Mashable

		The Teamwork Barnstar
		Good to see the collaboration here being recognized.[28] Congratulations to everyone involved! Clayoquot (talk | contribs) 18:34, 11 November 2020 (UTC)

Yup: And here is Mashable's Facebook link to the article. Kudos to all involved. RCraig09 (talk) 19:39, 11 November 2020 (UTC)

I though MurrayScience’s comments on how collaboration can result in work that is better than any one person would write was a particularly nice touch. Dtetta (talk) 19:44, 11 November 2020 (UTC)

Thanks! It really was a wonderful article about a wonderful wiki page. Congrats everyone. MurrayScience (talk) 21:16, 11 November 2020 (UTC)

You are a wonderful bunch to work with :). Very much agree that none of us could have done this alone. Femke Nijsse (talk) 19:23, 12 November 2020 (UTC)

... and here's the post from Wikipedia's Facebook page. —RCraig09 (talk) 21:29, 12 November 2020 (UTC)

Scientific Consensus Image

This image was deleted by Efbrazil.

It's not dated as the review study is from 2016. It also shows the actual scientific consensus, which is the subsection it is in. It's a better image than the current image to represent that subsection. The current image in that subsection should be replaced with this one again. Bogazicili (talk) 15:24, 12 November 2020 (UTC)

A review study concluded that "the finding of 97% consensus [that humans are causing recent global warming] in published climate research is robust and consistent with other surveys of climate scientists and peer-reviewed studies." The pie charts show the results of some of the climate consensus studies cited.

References

I think this is the better image indeed. I'm now on mobile and think it's readable, but ideally the font would be a bit bigger. The caption should be condensed a bit. Femke Nijsse (talk) 15:44, 12 November 2020 (UTC)

Efbrazil: is it editable? We could put the year on a next line and bump up don't size of the authors? Femke Nijsse (talk) 15:47, 12 November 2020 (UTC)

Using an image with a bunch of near 100% pie charts to emphasize a point that is already in the text without adding any substantive visual information comes across as heavy handed propaganda. The image could just be a bunch of text that was enlarged and in bold and red and blinking and it would have the same effect- e.g. "get it through your thick skulls that there is scientific agreement!!!". I understand the image I replaced it with has drifted from the text (the text used to talk about areas of scientific agreement and disagreement, not simply agreement). I would rather have no image in this location than the pie chart image. If I have time, I will try to restore some balance to the section in general. There are some very dodgy decisions that the IPCC has made that undermine their credibility, like using sleight of hand to ignore the carbon cycle in their reports in order to increase the certainty of their predictions. Efbrazil (talk) 17:34, 12 November 2020 (UTC)

The pie chart graphic is much more appropriate to the section than a chart of carbon sources and destinations. Assuming that the surveys themselves are reliably sourced, I think a fair graphical representation of those surveys does not constitute propaganda, either in substance or appearance. For a lay audience that is unlikely to read the text of an 8980-word article, a graphic that conveys the critical concept of scientific consensus is essential to this article. —RCraig09 (talk) 18:02, 12 November 2020 (UTC)

• I prefer no image to the current off-topic image, so that compromise would work for me. We are quite heavy-handed in this article with images and having one fewer will be good.
• These graphics are reliably sourced, and have been summarized in a peer-reviewed paper. I agree that it's not propaganda: it's a common feature of science communication that is done by a wide variety of scientists.
• It's nonsense that IPCC doesn't include the carbon budget (+uncertainties) prominently. It's in all of their summaries for policymakers. I hear way more often that the IPCC AR5 has overestimated uncertainty in future warming than the opposite among my colleagues.
• Always happy to get a new proposal for text here on the talk page. I'm especially keen on giving the 'warning to humanity' less prominence. Femke Nijsse (talk) 19:13, 12 November 2020 (UTC)

• I pulled the carbon sources and sinks image, although it pains me because I think it is very informative, just not a good fit in that location.
• Sourcing is not the issue, it's that they are presenting info that is not visual and are simply belaboring a point, not adding any informative value.
• In AR5 the IPCC explicitly changed their analysis to talk about CO2 concentrations (RPCs) instead of emission scenarios (SRES). My understanding is that they did that to eliminate the uncertainty that the carbon cycle introduced, which is roughly half of the uncertainty we have around expected global temperature changes. The sleight of hand is that all their asks of people are in terms of behavior relates to emissions and how we influence the carbon cycle, but all their analysis is based on RPCs. In other words, they obviously talk about the carbon cycle, but they ignore it where it counts- their predictions, which are all RPC based. Please correct me if I'm wrong.
• Thanks, will do if I get time. Efbrazil (talk) 20:45, 12 November 2020 (UTC)

I fail to see how this image is "heavy handed propaganda." That sounds like Psychological projection. The point of an image is also not necessarily to provide new information, but sometimes to summarize a point visually, which the deleted image did. The only thing to improve in the image would be to add another pie chart showing 89% agreement for (Verheggen et al (2014)). The other 80's are before 2010.[29]. This image is also better than the Sydney demonstration image, which looks like a generic demonstration. If too many images is the concern, we should get rid of Sydney demonstration image. Bogazicili (talk) 18:51, 15 November 2020 (UTC)

Created a RFC for this. Bogazicili (talk) 19:02, 15 November 2020 (UTC)

RfC about a photo in the Scientific Consensus section

Currently, there is no image in this section. On the right is the image suggested.

It comes from this peer-reviewed secondary source [30], which NASA also uses on their Climate Change facts pages [31]. The image does not contain the 3 lower percentages in the study, for agreement among "Sub-sample of publishing climatologists" (see table 1): 83.5% (2008), 88.5% (2005), 89% (2012).

Should we use this image, or another image, or edit this image (only contain cited studies newer than 2010 or all studies), or use no image? Bogazicili (talk) 19:02, 15 November 2020 (UTC)

Also note that the consensus reaches 100% as of 2019 [32], maybe that can also added into the image. Bogazicili (talk) 19:12, 15 November 2020 (UTC)

• Strongly agree with Bogazicili. On the principle that a picture is worth a thousand words, an image is essential to the critical concept of scientific consensus. Including a sentence or two in the text an 8980-word article is not sufficient to convey the overwhelming nature of scientific consensus to Wikipedia's lay audience. The pictured image is a good start. RCraig09 (talk) 19:25, 15 November 2020 (UTC)

• Comment I believe this request to be a bit premature. You're proposing both possible improvements to this figure, ánd a request to include this figure into the article. It would be better if you first work on improving the figure; making sure it's readable on phone for older eyes for instance as Efbrazil commented. Femke Nijsse (talk) 19:27, 15 November 2020 (UTC)

Suggesting improvements to the image is premature, given that you 2 are proposing no image. I'm wondering what people think about this image or a similar image first. If there is a consensus on an image like this, then we can work on the final version. Bogazicili (talk) 19:35, 15 November 2020 (UTC)

• Agree after text is make legible (just makign clear that my preference is a figure, just willing to compromise on none). Femke Nijsse (talk) 19:45, 15 November 2020 (UTC)
• I have made a new SVG with larger text for names. On my system I see a slight font rendering problem for the top title line (shifted too far right); if you see it also, maybe we should just use an updated JPG: File:Cook et al. (2016) Studies consensus.jpg? This is a pesky, apparently inescapable problem with SVG font renderings. RCraig09 (talk) 06:57, 16 November 2020 (UTC)

• Strongly oppose. Using an image with a bunch of near 100% pie charts to emphasize a point that is already in the text without adding any substantive visual information comes across as pure bias. The image could just as well be a bunch of text that was enlarged and in bold and red and blinking and it would have the same effect- e.g. "get it through your thick skulls that there is scientific agreement!!!". There are already too many graphics in the article according to femke, let's not make the article worse by cluttering it with a collection of 100% pie charts. For more information on why this is a bad idea, see Wikipedia:Neutral point of view. Efbrazil (talk) 17:57, 16 November 2020 (UTC)

Consider talking more about the future

I kind of get information overload when reading this article. But one of the high level things I was looking for, was a succinct paragraph on what a year 2100 Earth looks like with everybody's CO2 emissions staying the same. Or just any summary of the main problems that un-checked global warming causes.

Yes, the trees have more pests, and some permafrost melts. But those issues by themselves are surely not the main reason that people are sounding the alarm.

What are some of the serious problems that late stage global warming would cause? Uninhabitability of the equator? Crop disruption and famine? Quadruple the number of hurricanes?

Did I fail to see this info? Or do we need to insert a succinct paragraph or two somewhere to cover this?

Thanks for your time. – Novem Linguae (talk) 07:27, 18 November 2020 (UTC)

I just ran across the Climate apocalypse article, which seems to discuss this topic in depth. Perhaps adding a link to it somewhere in this article, or putting a See Also or Main Article template somewhere, would be appropriate. – Novem Linguae (talk) 07:41, 18 November 2020 (UTC)

1964 Reference

Popular Mechanics, Aug 1964, p 81 on: https://archive.org/details/PopularMechanics1964/Popular%20mechanics-08-1964 'The Air around Us: How it is changing'