Talk:Climate change

Intro & Lemma

Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Sorry to say so, but these two sentences are wrong, as they contradict themselves. I don't want to criticise the content, but the terminology. First sentence says: CC is human-induced global warming, caused by the GHG emissions of human activities. Second sentence says: there have been CC events in the paleo-historical past. As humans were not responsible for these, the first and second sentence do not fit together. By the way, the term climate change just naked without adjective such as man-made or antropogenic just means that the climate is changing - due to any reason whatsoever.

The term "climate change" became popular 20 years ago when spindoctors advised the Republican party in the battle about the interpretive authority within the global warming debate. It was recommended to use the term "climate change" rather than "global warming", because it sounded less threatening. From a technical analysis, 'global warming' is more precise than 'climate change', because global cooling is also a type of climate change, and that is not what we can observe in the temperature records since the 1970s. But it is lacking either the cause (man-made) or a temporal domain (current). There have been global warmings in the past, eg. 12,000 years ago.

The IPCC has the term 'climate change' in its name, but they do not only cover the current global warming period which is man-made. The also cover research about past climate proxies, see e.g. Chapter 2: Changing state of the climate system, in the recent IPCC AR6 WG1 Full Report.

If you want to use an appropriate lemma for the current situation of +0,2 °C warming per decade and +0.45 °C per 1000 Gt CO₂, I would suggest to name this online piece of literature here climate crisis, as other paleoclimate changes could not be misinterpreted as a crisis for the current population. Of course, the content of climate crisis needs to be integrated here. Or go back to global warming as it was common before the language softener took over. --Gunnar (talk) 21:18, 28 August 2021 (UTC)

You make many good points, but the word "includes" does not limit climate change, so there is no contradiction in the quoted passage. By way of background, a couple of years ago there was made a distinction between this article (which is about human-induced climate change) and "Climate change (general concept)" which now redirects to the broader, more inclusive concept Climate variability and change. The present article is, after much discussion, where the consensus decided to be the destination of readers wanting to learn about human-caused global warming or human-caused climate change; in fact, searching for "global warming" now redirects here. Also after much discussion, Climate crisis was confirmed to be inappropriate for this content because the term crisis is non-neutral, whereas change is neutral and objectively descriptive. I hope this wiki-history clears things up. —RCraig09 (talk) 21:56, 28 August 2021 (UTC)

Still, the first sentences have an imprecise wording. "Climate change includes both A and B. And there have been previous periods C of climatic change." This does not introduce in the very first lines what climate change actually is, if any other options D and E (such as cooling) could be included as well. The scope is not really described. "Climate change comprises large-scale long-term shifts in weather patterns, especially the current global warming driven by human-induced emissions of greenhouse gases. Though there have been previous periods of climatic change in paleontological history, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale, see Anthropocene."--Gunnar (talk) 22:13, 5 September 2021 (UTC)

As this article is solely about current climate change, this proposal may confuse people. I think we may want to move to a sentence without bolding, like 'Global temperatures have risen 1.1 degrees since pre-industrial times, driving further changes in large-scale weather'.

As a minor point, the words comprise and palaeontological are not appropriate for an article also read by teenagers and people without further education. FemkeMilene (talk) 06:51, 6 September 2021 (UTC)

The beauty within a wiki-universe is that you can easily link difficult words but which are technical terms such as paleontology to an article which explains the full term. And I think it is a little bit sassy that you assume that Wikipedia readers are not able to learn new terms - they have learned to read at least. The intro is still wrong, as the article is about - as you wrote - about the current climate change only. Therefore you can't say climate change is blablabla and not mentioning the general concept. It is needed to add a qualifier to the introduction. I do prefer man-made or antropogenic instead of current. --Gunnar (talk) 13:55, 30 September 2021 (UTC)

"Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns." - This sentence is still nonsense and highly unprecise. First, "large-scale shifts in weather patterns" is another word for climate change. So climate change is climate change? I strongly believe that circular definitions are not helpful at all, and for all sympathy for simple reading we should not be lead towards writing only nonsense here which main advantage is that it can be spelled by first graders. There are different flavours for climate change, in time and sorted by trigger elements. Obviously the article's lemma omits the word anthropogenic / man-made / current or any other qualifier which gives a proper description which kind of flavour is adressed below. If this omission is done due to popular and mainstream use of the shortened form "(xxx) climate change", the article itself should start with a proper declaration what the precise scope is.

The current climate change, meaning the recent large-scale shifts in weather patterns including global warming, is driven by human-induced emissions of greenhouse gases, mainly carbon dioxide from fossil fuels.[AR6 WGI] Though there have been previous periods of climatic change, since the beginning of the Industrial Revolution and especially the 1970s humans have had an impact on Earth's climate system with an unprecedented rate of change.

As far as I know, the 'unprecedented' part is not the size of change itself - that is stil only a degree C or so - the but the speed or ramp rate (0,2 °C per decade). Or are there any climate fluctuations in the past (e.g. the 8.2 ka event) which had similar gradients? --Gunnar (talk) 18:43, 30 September 2021 (UTC)

I agree that the second sentence should revert back to stating that the rate and scale of change is unprecedented, per SR15. We do not mention the 1970s in the body, so we cannot mention it in the lede.

I'm not quite happy with the Gunnar's proposed first sentence, which should be shorter in my opinion. I do however agree change is warranted, either by specifying which climate change explicitly (current), or by specifying the cause (Human-induced emissions are raising global surface temperatures, resulting in large-scale shifts in weather). I would like opinions on whether people feel okay with proposals that do no words climate change and global warming explicitly to get a more natural-sounding sentence. Will come up with a few proposals over the weekend depending on energy. FemkeMilene (talk) 19:30, 30 September 2021 (UTC)

Climate change

The effects of synthetic substances on the earth’s atmosphere are increasingly being recognised as problematic. They are partly responsible for climate change. [Unsigned]

We knew... 2603:9000:A703:1EFD:406B:9711:8BCA:FC22 (talk) 15:04, 15 September 2021 (UTC)

Did we forget that and do not know anymore? --Gunnar (talk) 18:45, 30 September 2021 (UTC)

Improving the readability of this article, including key climate change terms

I was listening to a Science Friday podcast last week about how confusing climate change terms can be to the general public. The podcast itself is here, and the research paper being discussed is here. It got me thinking that we should look at this article in light of that research, and try to improve how we are describing some of these key terms, like “mitigation” and “tipping points”.

On a related topic, the research paper led me to look into the general readability of the Climate change article. So I used Readable.com to evaluate it. The “Observed temperature rise” section received a D grade, with a Flesch-Kincaid Grade Level of 12.5, a Gunning fog index of 14.0, and a Flesch reading ease score of 43.5 (scale of 100-higher is better) - indicative of a college level type of text. When I tried other sections, the results were similar, and interestingly enough, the lede paragraphs received some of the lowest scores in terms of readability.

In comparison, NASA’s Climate Change website scored a 9.2 and 9.1 on these same measures, indicating a beginning high school readability level. The Flesch reading ease score for that web site was 48, and the site received an overall grade of B. National Geographic’s Climate change website, the other one that typically scores near the the top of my Google searches for Climate change, gets similar scores on Readable.

I didn’t see any specific WP guidance on what an appropriate level of readability for an article (or target grade/age level) is. The WP:MTAU page does talks about general techniques that can be used when trying to make technical articles more readable. My understanding is that, in the US, we generally shoot for an eighth grade reading level when creating webpages for the public. That’s pretty close to how the NASA and National Geographic sites score.

So I have a couple of general questions for this group of editors. 1-Do you think that we need to improve the readability of the Climate change article, and try to lower the target reading level of the text? 2-More specifically, should we devote some effort to creating more understandable descriptions for some of these critical climate change terms?

I thought about making this an Rfc, but instead I am mentioning Femke, Sadads, Efbrazil, RCraig09, Bogazicili, Clayoquot, Chipmunkdavis, NewsAndEventsGuy, and Chidgk1. Any thoughts you all have on this would be most appreciated.Dtetta (talk) 04:08, 16 September 2021 (UTC)

Don't have time to check the links right now, but the specific part of WP:MTAU that applies is WP:ONEDOWN, which for this topic would suggest as low a base as possible. 8th grade sounds a good target. CMD (talk) 04:20, 16 September 2021 (UTC)

Dtetta, yes please!! I have always been pushing for improving readability of Wikipedia articles on science type topics. Most of them are quite hard to read, especially also for non-native English speakers. So I am all for it. I have (for example) written about it here under Task 3, linking also with my favourite assistant tools for this (they are just assistants, the work has to be done by a capable editor, of course). EMsmile (talk) 08:15, 16 September 2021 (UTC)

I'm a bit surprised, as we've put in quite some effort in making it understandable already,but I'm keen to hear suggestions / see bold edits to improve the ease of understanding :). FemkeMilene (talk) 08:34, 16 September 2021 (UTC)

Actually you are right, Femkemilene, the readability has recently improved a lot - sorry I wasn't quite up to date here! I had last checked it about 6 months ago with this tool: https://www.webfx.com/tools/read-able/check.php?tab=Test+By+Url&uri=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FClimate_change At that time, it only scored 40.5 for the Flesch score. Now when I use the current version it's 57.5. That's an excellent improvement. (Higher than 60 could be aimed for but is very hard to achieve.) But many of the closely related topics, e.g. effects of climate change, greenhouse gas emissions still need the same kind of improvements. :-) Question to Dtetta, what exactly do you mean with this: "2-More specifically, should we devote some effort to creating more understandable descriptions for some of these critical climate change terms?" Are you referring to sub-articles? EMsmile (talk) 08:55, 16 September 2021 (UTC)

Thanks for those comments EMsmile, sorry I didn’t include you on the original list of mentions! It’s good we’re looking at the readability issue with a couple of different tools. But I’m concerned that the Web FX tool, when evaluating a URL, is not accurate (it does seem to do well when you actually have it read a sample of text, like Bogazicili did)). I believe that 57.5 score is way too high, and it’s based in part on a words per sentence count of less than 6, which is way too low. I compared their URL results with text results (based on inputing text, with citation numbers deleted) for the lead paragraphs. That score shows a much higher reading level, and much lower Reading Ease score. I used the same text on the Readable site, and the Readable score is pretty consistent with what Web FX shows. So I’m pretty sure that in terms of reading level/readability criteria, the article scores somewhere in the 12th grade/college level, again much higher than either the NASA or National Geographic websites, and higher than what I remember as general web guidance for target reading level, which is 8th grade. Dtetta (talk) 00:01, 17 September 2021 (UTC)

And thanks for including that Task 3 link! Nice to now you are already working on this issue. The ideas listed there make good sense to me:) Dtetta (talk) 02:22, 17 September 2021 (UTC)

I also checked the January 1st version of the lead before we made changes, using [1], and there has been a slight improvement in the Flesch Reading Ease score. Feel free to make suggestions. I think the need to summarize lots of information is leading to longer sentences though, which reduces the score.Bogazicili (talk) 11:44, 16 September 2021 (UTC)

We could probably apply some of the recommendations from the paper. Recommendation #1 is "Avoid technical language (i.e. jargon)"; part of our job is to help the reader learn useful terminology so we shouldn't avoid jargon altogether, but we can try to improve the timing of when we introduce it. For instance, "mitigation" is jargon and "reducing emissions" or "limiting climate change" are plainer language. We could use the plainer terms in the lead and in the headings that appear in the TOC. Then in the first paragraph of the section that deals with limiting climate change, say that efforts to limit climate change are technically known as mitigation.

Going a level deeper, another suggestion from Wikipedia:Make technical articles understandable is to put the least obscure parts of the article up front. The "Drivers of recent temperature rise" section includes a lot of facts that I would consider highly obscure. I'd try to move most of this to the end of this article.

Going two levels deeper, I know a lot of progress has been made in terms of triaging how much technical detail to include on the physical science aspects of climate change, but I think we still have too much detail on climatology that isn't relevant to the general reader. For example, I understand all the words in the following sentence (I have a chemistry degree), but I just don't get what it's trying to tell me: "Aerosol removal by precipitation gives tropospheric aerosols an atmospheric lifetime of only about a week, while stratospheric aerosols can remain in the atmosphere for a few years." Rather than trying to improve all the sentences like this one, it's worth considering having fewer of them. Clayoquot (talk | contribs) 22:13, 16 September 2021 (UTC)

Thanks Clayoquot - those are great suggestions. I agree with all of them, although I have a slightly different take on the “Drivers of recent temperature rise” section. I think that a simplified, less IPCC centric version of that section should remain near the top of the article. The reason I say that is because I think that’s one of the key things people want to understand- what exactly is causing climate change. I am assuming there are four key questions for a reader of this article: 1-How much global warming is happening/will happen? 2- What’s causing it? 3-What are the effects? and 4- What can be done? The “Drivers of recent temperature rise section” addresses that second question, but I think you’re correct in saying it does so at times in an obscure, jargon heavy way.

So far I think you and EMsmile are the ones most in favor of making changes to address the readability issue. I’ll wait a couple more days to see if there’s any other responses, and then propose some more specific follow up ideas, likely along the lines of what you’ve suggested. Dtetta (talk) 02:31, 20 September 2021 (UTC)

To put a more personal note on this, I was listening to another Science Friday episode last week, dealing with how we can “co-exist” with wildfires (that’s how the intro reads). During the discussion, the researcher being interviewed talked about changes that, from my perspective, are ways to “adapt” to increased wildfire risks, such as controlled burns and home hardening (which basically involves creating a zone around your home that is free of highly combustible trees and shrubs). But that person used the term “mitigation” to describe these measures. If we were to describe these actions, would we label them as mitigation or adaptation? Not looking for an answer, but I think it’s a good example of the limits of overly technical terminology when we’re trying to help the reader understand these issues. Dtetta (talk) 21:41, 20 September 2021 (UTC)

Yes, the way the term "mitigation" is used in climate change is different from most other contexts. The term "noise mitigation", for example, usually means putting up sound barriers or other stuff to muffle and block noise before it reaches the listener. It doesn't usually mean reducing noise at the source. Clayoquot (talk | contribs) 22:11, 20 September 2021 (UTC)

I support any effort to improve readability, but past efforts have caused content to drift away from sources or have led to lazy over generalizations without context, like what happened when we presented extreme numbers on particulate based pollution deaths without any context on indoor vs outdoor, rich vs poor countries, pollution controls vs limiting combustion, etc. The difficulty is exacerbated by the fact that we don't provide quotes from our sources inline, so the grounding for what we write is unclear and difficult or sometimes impossible to find in the source materials. So I guess my vote is go ahead but be sure to keep context around the grander claims. Efbrazil (talk) 18:56, 22 September 2021 (UTC)

Is this a kind of idiocracy trick question? Complex problems need a detailed and sometimes complex explanation. Regarding Clayoquot's question about the aerosols: Rain washes particles from the lower layers of the atmosphere, the troposhere, where clouds are forming and rain is often falling out of clouds much faster than in the stratosphere. In theses higher levels clouds are rarer and rain is almost non-existent, so aerosols are kept there where they are. --Gunnar (talk) 14:11, 30 September 2021 (UTC)

I agree with Clayoquot that the sentence about aerosols doesn't have a clear goal. Mentioning tropospheric aerosols (or simply "most" aerosols)'s short lifetime is probably warranted to explain that stopping emissions may have a slight warming effect in some regions in the very short term, but stratospheric aerosols just aren't that important for our audience.

@Gunnar.Kaestle: could you please tone it down a bit? You're not winning people over by calling their questions idiocracy. FemkeMilene (talk) 19:36, 30 September 2021 (UTC)

Femke, have you watched the the Idiocray movie? They had a food problem because they irrigated their crops with some kind of sugary soft drink: just use water - problem solved. Same for the man-made climate change: stop emitting CO2, don't burn fossil fuels - problem solved. If you want to go into detail then you will need a more complex description of what happens in the different subsystems. To show all the scientific research, in order to gain credibility, I would not reduce neither language nor content on an 8th grader's level. It helps to avoid jargon or at least to explain technical terms - because many other publications are written with those and the reader should be enabled to understand papers which are referenced here or which he may find elsewhere. Thus, the option of playing bullshit bingo with the articles texts should be minimised be just calling a spade a spade. This includes the introduction, as not all page visitors will read the full article, but just the first few lines and they may opt in for interesting sub-chapters. Gunnar (talk) 22:21, 30 September 2021 (UTC)

Per WP:EXPLAINLEAD, we should avoid jargon in the introduction. The introduction doesn't really have the space available to (implicitly or explicitly) explain jargon. We can be a bit more technical in the main article, aiming for a 15/16-year old audience, which keeps things simple without insulting more educated readers.

P.S. not all of our readers are a 'he', and the words 8th grader don't mean much to people outside of your countries' education system FemkeMilene (talk) 09:41, 2 October 2021 (UTC)

I agree with Gunnar.Kaestle that we should not aim at 14 year old (8th grade) readability in the main body - I think that would be an impossible target and would just depress editors when we failed to reach it. But I agree with Femke that 16 year old readability could be a target ("aspirational" I think) for the main text - because many native English speakers have not had formal education beyond 16 - and people who want more technical detail can click through to more detailed articles. And I agree with Dtetta that readability needs improving and that "mitigation" and "tipping points" are confusing. And I agree with Clayoquot that non-vital info should be cut out (perhaps moved to other articles). Re key climate change terms when I google for "climate change words" Glossary of climate change is 4th of non-ad sites. The Google "featured snippet" is out of date e.g. it has INDC instead of NDC. Should I write to a Wiki-Ed and ask if they can persuade some students onto Glossary of climate change?

P.S. I am glad that Nat Geo site does not appear on the first page of my Google results as I think their "lead" is misleading. Will take a look at the NASA site. Chidgk1 (talk) 14:56, 2 October 2021 (UTC)

Dtetta's proposal

Glad to see there has been more discussion on this. Below is a proposed revision to the first two paragraphs of the lede, just as an example of what could be done to improve readability for specific text, based on results from the readable.com and hemingwayapp.com (H/T to EMsmile) sites for those two paragraphs. Again, just trying to show the potential of this technique.

Based on the results I was seeing when I started with those sites, I focused mainly on reducing the number of long sentences, cutting them up into shorter ones. This is what the changes look like in underline/strikeout form:

Human-induced c Climate change includes both human-induced global warming driven by emissions of greenhouse gasses and its the resulting large-scale impacts on shifts in weather patterns. Though tThere have been previous periods of climatic change in Earth’s history. But since the mid-20th century humans have had an unprecedented impact on Earth's our climate system and caused change on a global scale. The largest driver main cause of global warming is the emission of greenhouse gases, that create a greenhouse effect, of which more than 90% are mainly carbon dioxide (CO2) and methane. Burning fFossil fuels burning (coal, oil, and natural gas) for energy use, steel, and cement production consumption is the main source creates most of these emissions. with additional contributions from aAgriculture practices and forest lossdeforestation, and manufacturing are also significant sources. The human cause of climate change is not disputed by any scientific body of national or international standing. Some types of climate change can even act as a feedback mechanism, accelerating or slowing down the rate at which warming occurs. This can happen through Temperature rise is amplified by climate feedbacks , such as the loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself), and or changes in the amount of CO2 that the to land and oceans can absorb back. carbon sinks.

And this is what the actual text would look like:

Climate change includes both human-induced global warming and its large-scale impacts on weather patterns. There have been previous periods of climatic change throughout Earth’s history. But since the mid-20th century, humans have had an unprecedented impact on our climate, and caused change on a global scale. The main cause of these changes is the emission of greenhouse gases, mainly carbon dioxide (CO2) and methane. Fossil fuel burning (coal, oil, and natural gas) for energy use, steel and cement production creates most of these emissions. Agriculture practices and forest loss are also significant sources. Some types of climate change can even can act as a feedback mechanism, either speeding up or slowing down global warming. This can happen through the loss of sunlight-reflecting snow and ice cover, or via changes in the amount of CO2 that the land and oceans can absorb back.

As you can probably tell, I made a few other changes along the way that seemed needed (and often improved the readability score). I broadened the description of impacts/effects in the first paragraph to more than just weather patterns. In the second paragraph I specified the types of chemical manufacturing, and changed some of the feedback text to make it a little less technical/jargony. I also deleted the water vapor reference to make the list of feedback examples shorter, although the water vapor effect is an important feedback. This was another instance where an edit caused a significant improvement in the readability score, but maybe water vapor is worth keeping in nonetheless.

Lastly, I think the most significant change I made was to delete the reference to the human cause of CC as not being disputed, as this didn’t seem to me to fit with the rest of the second paragraph, and it’s a somewhat convoluted sentence. I still think it’s important to make this point somewhere in the lead, but I’m just not sure where. One possibility would be to have something like “These ideas have near unanimous scientific consensus behind them” as the last sentence of the first paragraph. I'm sure there are other ways of doing this as well.

These edits brought the Flesch-Kincaid Grade level down from about 15 to about 10, and raised the reading ease score from 35 to 54, both major improvements. The grade level on the Hemmingway site goes from to Post Graduate to Grade 11. Although these measures clearly aren’t the only factors to be thinking about, the text does seem to be more “readable” to me.I think the only loss of detail has been the deletion of the scientific consensus and water vapor references, and I believe there is an alternative way of capturing the scientific consensus concept.

Here is a link to the report from readable.com for the original two paragraphs: https://drive.google.com/file/d/1fBQUdQHFVBkl9YQeD5oknRRzsr8zwL0S/view?usp=sharing

And here is a link to a report for the revised paragraphs: https://drive.google.com/file/d/17gwJ5jaGhMqARXf4L5Bv-aO-1hQyWsXv/view?usp=sharing

If folks think this is worthwhile, I could continue with paragraphs three and four. My sense is that paragraph five is fairly readable as is, but it might benefit from a couple of minor edits as well. Or we could think about making these proposed changes as actual edits.

Notifying Femke, Clayoquot, EMsmile, Efbrazil, RCraig09, Bogazicili, Chipmunkdavis, NewsAndEventsGuy,Sadads, SandyGeorgia and Chidgk1 Dtetta (talk) 15:27, 4 October 2021 (UTC)

And based on the first couple of responses to this post today, it seems like I neglected to clarify what I am specifically asking for in terms of feedback. For me it’s clear that using shorter sentences, and striving for less technical wording, improves the readability scores of these paragraphs. Do you think these kinds of changes in general are an improvement? And should we try to do this for the other paragraphs in the lede? Dtetta (talk) 18:02, 4 October 2021 (UTC)

Discussion first paragraph

First sentence
Editors may edit their own proposals, add proposals, or designate support in this Consensus Chart

Note from Dtetta - when choosing sentences, please cut and past your combined choices, and look at the resulting paragraph as a whole before you make your individual choices.

Major new approach (without explicit definitions of CC or GW)

• Human activities, mainly the burning of fossil fuels, are driving up global temperatures. This is resulting in long-term and large-scale shifts in the climate. —FemkeMilene

Supported by: Femke, ___

• (variation of above:) . . . . This is causing large-scale and long-term climate change. FemkeMilene—

Supported by: Femke, ___

• Human activities, mainly the burning of fossil fuels, are driving up global temperatures. This global warming is causing long-term and large-scale climate change. —RCraig09

Supported by: RCraig09, Chidgk1, ___

• Climate change includes both human-caused global warming and its large-scale impacts on weather patterns.-Dtetta (Grade level 9.1, Reading ease 58)

Supported by: Dtetta, ___

• Status quo: "Human-induced climate change includes both global warming driven by emissions of greenhouse gases and the resulting large-scale shifts in weather patterns." (Grade level 12.9 Reading ease 44)

Supported by: Femke, ___

• __________

Supported by: ___, ___

Start of first sentence (incremental approach; may be moot)

• start with "Modern-era climate change..." —RCraig09

Supported by: RCraig09, Femke?

• start with Human-made climate change... —Chidgk1 10 Oct 2021

Supported by: ___, ___

Ending sentence(s), or Both sentences

• (omit phrase altogether) Though there have been previous periods of climatic change, since the mid-20th century Humans have had an unprecedented impact on Earth's climate system and caused change on a global scale. —RCraig09

Supported by: RCraig09, ___

• There have been previous periods of climatic change throughout Earth’s history. The period since the mid-20th century is unique, as humans have had an unprecedented, global-scale impact on our climate.” —Dtetta (Grade level 10.9, Reading Ease 45)

Supported by: Dtetta, Femke?

• (Status quo-no change) Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale. (Grade level 15.2, Reading Ease 41)

Supported by: Dtetta (2nd choice), ___

• There have been previous periods of climate change, but the current warming is more rapid than any known events in Earth's history.

Supported by: Femke, Chidgk1, ___

First and second sentences

• Climate change includes both human-induced global warming and its large-scale impacts on weather patterns. There have been previous periods of climate change, but the current warming is more rapid than any known events in Earth's history. —Dtetta

Supported by: Dtetta, Femke ("green light"), RCraig09 (acquiesce)

Let's start with the first sentence. The first sentence is meant to define the scope of the article. Usually it is done by giving a definition. The new definition given is incorrect: most definitions only include atmospheric changes, not impacts on ecosystems. But I believe we should step away from giving a definition entirely. Having a definition has always been finicky for us, as climate change has two overlapping definitions (current / general), so that the prose becomes awkward if you say "Climate change is" or slightly less awkward "climate change includes". I would prefer something along the lines of Human activities, mainly the burning of fossil fuels, are driving up global temperatures. This is resulting in long-term and large-scale shifts in the climate. FemkeMilene (talk) 16:17, 4 October 2021 (UTC), adjusted 16:46, 4 October 2021 (UTC)

That’s a fair point, although this site from NOAA clearly combines the concepts. I think your suggested wording is fine. Are you suggesting that as the first sentence in paragraph? Dtetta (talk) 17:20, 4 October 2021 (UTC)

It's unorthodox to avoid formally defining the titular concept, but because of the varying and possibly overlapping definitions of CC and GW, it's understandable in our situation. I suggest the following so that GW and CC are defined inferentially (in bold): Human activities, mainly the burning of fossil fuels, are driving up global temperatures. This global warming is causing long-term and large-scale climate change. —RCraig09 (talk) 20:20, 4 October 2021 (UTC)

Support GW and CC are defined inferentially and RCraig09 sentence in green. Chidgk1 (talk) 07:31, 5 October 2021 (UTC)

I'm not convinced by the second sentence. If the goal is to have bolded text, note that per MOS:BEATLES, second sentences are not allowed to have bolding. It's an obscure rule, so maybe we can get away with it. What about This is causing large-scale and long-term climate change? This steps away from the problem that global warming is part of climate change, so that it cannot really cause it. FemkeMilene (talk) 08:31, 5 October 2021 (UTC)

Burning fossil fuels, and other human activities, are causing global warming and long-term and large-scale climate change.? Chidgk1 (talk) 08:50, 5 October 2021 (UTC)

(After edit conflict; not in response to Femke's 16:17 post) Initially, I would tweak Dtetta's text:

1. ... start with "Modern-era climate change..." to distinguish what this article focuses on
2. ... join the second and third sentences as they are so closely intertwined (~never start a sentence with "But").

—RCraig09 (talk) 16:19, 4 October 2021 (UTC)

So please keep in mind that it is those long, run on sentences that make the text harder to read, according to the professionals in this field, as I understand it. That was the whole purpose of the exercise. As an alternative, we could use “however” rather than “but”, or any other word that would introduce the contrast between the two shorter sentences. Dtetta (talk) 17:07, 4 October 2021 (UTC)

You might also find this reference on whether or not to use “and” or “but” useful. Dtetta (talk) 19:49, 4 October 2021 (UTC)

This discussion will be moot if Femke's major new approach prevails, so I'll merely state that the current 31-word sentence is long by some standards, but it is clear. It distinguishes in one sentence, modern-era CC from earlier CCs. —RCraig09 (talk) 20:08, 4 October 2021 (UTC)

So I’d like to reboot this discussion of the first paragraph, if folks don’t mind. First, it was clearly a bad choice on my part to try to revise the original “weather patterns” text, particular since it seems to have gotten us focused on details rather than the overall readability issue. In the paragraph above I am reverting that edit, so that “weather patterns” is back to roughly where it originally was. I’ve archived my original proposal here if anyone wants to see it.

And just to clarify what I did (and why). In the first sentence I condensed the wording to reduce the word count from 23 to 16. The phrase “the resulting large scale shifts in” has been changed to “its large scale impacts on”, which increased the reading ease score by 0.6 points. At the end of the paragraph, the original 31 word second sentence has become an 11 word sentence and a 22 word sentence. And even that 22 word sentence is consider long from a readability standpoint (it’s one of the pink highlighted sentences in the readable report)

Rather than get side tracked on a discussion of whether the article should start with a definition (from what I’ve seen that does in fact seem to be a typical technique in WP articles), I’m hoping additional comments can focus on the changes I’ve described above. For instance, RCraig09 seems to prefer the longer final sentence rather than the two that I have created. My view is that the only reason for having a really long sentence is that the ideas are so intertwined that they can’t be separated without a loss of meaning. But in this case these are two distinct concepts that you can connect with a conjunction type word or phrase. Not saying my perspective is necessarily the correct one. What do others think? Dtetta (talk) 06:51, 5 October 2021 (UTC)

In general short sentences are more readable (my Economist style guide got lost in the post - I wonder if I can buy it on Kobo - but pretty sure it said that in one I had years ago) so they should be the default and it should be up to the person proposing a long sentence to come up with a convincing justification Chidgk1 (talk) 07:25, 5 October 2021 (UTC)

If we break into two sentences, the "previous periods..." sentence would constitute a sentence in the first paragraph of the lead that does not even pertain to the subject of the article(!) That's why I favored binding it to the "unprecedented impact..." sentence—purely for distinguishing the two. Upon reflection, that distinction sounds "defensive" toward denialism. If our goal is to simplify, then we could omit the "previous periods..." sentence altogether, thus solving two problems at once. —RCraig09 (talk) 19:11, 5 October 2021 (UTC)

That might work. I like having the two concepts, though. We could borrow some of the tone from the first two paragraphs of this NASA webpage, and have the last sentence read:” The period since the mid-20th century is unique, as humans have had an unprecedented, global-scale impact on our climate.” Dtetta (talk) 21:16, 5 October 2021 (UTC)

The phrase including "...unique" sounds a bit WP:SYNTHish in approach. The term "unprecedented" seems to cover that concept already so I'd still favor the single-phrase approach. —RCraig09 (talk) 04:25, 6 October 2021 (UTC)

Fair enough - given the ongoing concerns you still have, I’m ok with keeping that last sentence the way it is, even though it’s long. Other thoughts on this? Dtetta (talk) 12:45, 6 October 2021 (UTC)

I'm concerned about the sentence, since it has drifted away from the sourcing. I don't mind it being commented out if we implement something along my first sentences or leave it be for a later discussion. I'm not proposing an alternative before I'm recovered. FemkeMilene (talk) 12:55, 6 October 2021 (UTC)

I'd like to have a try simplifying a sentence from the body for the second sentence of the lede (as the status quo isn't entirely supported by the sources). However, the modern observed rise in temperature and CO₂ concentrations has been so rapid that even abrupt geophysical events that took place in Earth's history do not approach current rates.[38] -> There have been previous periods of climate change, but the current warming is more rapid than any known events in Earth's history. This would allow us to shorten the sentence, get lead-body consistency (a GA/FA criterion), and allow for a previous goal of linking climate variability and change. I've not rechecked the source. Femke (talk) 19:49, 8 October 2021 (UTC)

Don’t see a real consensus around any of the text alternatives that are presented in the poll that was created. So I’m proposing the following revision for the first paragraph. Basically, modifying the first sentence with something close to my original proposal (minus the “ecosystem” faux pas). Then shortening the second sentence by eliminating the reference to historical climate change, which was a suggestion RCraig09 made on 5 October. Grade level improves from 14 to 10.1, and reading ease increases from 43 to 56 for the paragraph. The main content changes are eliminating the reference to greenhouse gases, which is a concept we cover the second paragraph, so it’s eliminating some redundancy. In the first sentence, changing the phrase “the resulting large scale shifts in” to “its large scale impacts on” is a slight readability improvement, and also reinforces the term “impacts”, which is repeatedly used in the article. “Impacts” is used twice in the paragraph, so this might be seen as redundant; some might also find issue with what the word “its” refers to, so feedback on these points would be helpful. Keeping “induced” rather than “caused” or “made” in that first sentence. For the second sentence, I’m using Femke’s 8 October proposal (assuming the sourcing is good), which is also supported by Chidgk1.

In terms of the more significant first sentence revisions that Femke snf RCraig09 have proposed, I would suggest we have that as a completely separate discussion topic, as going with non-definitional first sentences seems different from the current practice on many WP articles. The references to emissions are also redundant with the starting ideas of the second paragraph, so that may need to be edited as well if we want to make changes in the first paragraph along those lines. I would also note, that when we were having one of the earlier debates on the article title, I mentioned that the head of the Yale Program on Climate Communication liked how we distinguished between CC and GW at the start of the article.

So here is the actual proposal:

Climate change includes both human-induced global warming and its large-scale impacts on weather patterns. There have been previous periods of climate change, but the current warming is more rapid than any known events in Earth's history.

— Dtetta (talk

Green light from me :). Femke (talk) 22:20, 9 October 2021 (UTC)

° The first sentence starts by asserting an unqualified broad definition: "Climate change includes...". However the rest of the sentence is a definition of only the "Modern-era" climate change that is now the subject of this article. I think the lead sentence should start with "Modern-era CC includes..." to clarify that important distinction.

° If we're abandoning Femke's no-formal-definition approach, though, what you suggest is an improvement over the status quo, and I echo a green light. Make it so. —RCraig09 (talk) 03:10, 10 October 2021 (UTC)

I like that:) I think we are ok with the current wording, though, as Webster’s definition recognizes that nuance in the terminology. —Dtetta (talk

@Dtetta: I do not think a secondary definition in a general online dictionary "cures" this issue. An encyclopedia's lead definition should not raise red flags of ambiguity, especially when many people think modern-era CC is just another example of historical CC. —RCraig09 (talk) 15:27, 10 October 2021 (UTC)

@RCraig09: I’m looking at various websites and how they define climate change, and I’m still not seeing the need for the “modern-era” distinction. But if you want to make that change, I’m ok with it. Dtetta (talk) 21:36, 10 October 2021 (UTC)

The concern is not about whether others use "climate change" in the same way; the concern is that the term is overly broad in this context, especially for a lead definition.

Hopefully other editors will weigh in here... —RCraig09 (talk) 22:02, 10 October 2021 (UTC)

Doesn't the word "current" clarify this issue? "There have been previous periods of climate change, but the current changes are more rapid than any known events in Earth's history."? Doesn't this clarify the scope of the article and the term? In wiki terms, current climate change is the Wikipedia:Disambiguation#Primary_topic. Bogazicili (talk) 23:43, 10 October 2021 (UTC)

To be extra clear about the scope of the article, we might consider adding the following part in bold into the disclaimer on top:

'"Global warming" redirects here. This article is about the current Climate Change. For climate trends throughout Earth's history, see Climate variability and change. For other uses, see Climate change (disambiguation) and Global warming (disambiguation).' Bogazicili (talk) 00:05, 11 October 2021 (UTC)

Modifying the WP:Hatnote is a great idea! I'd use "modern-era" CC rather than "current" CC because it's almost two centuries old, not merely "current". Since the first sentence defines the subject, I think that definition should be made definite with "Modern-era CC...". —RCraig09 (talk) 03:41, 11 October 2021 (UTC)

I think it's really bad prose to have three hyphenated adjectives in a sentence. I think we need to leave out large-scale if modern-age gets added. Femke (talk) 12:47, 11 October 2021 (UTC)

Suggestion: Modern-era climate change includes both human-induced global warming and its large-scale impacts on Earth's weather patterns. —RCraig09 (talk) 15:23, 11 October 2021 (UTC)

Tbh, I find modern-era to be vague, it could mean starting from 16th century (eg: History_by_period#Modern_history_(1500_–_present)) Bogazicili (talk) 22:02, 13 October 2021 (UTC)

@Bogazicili: The CC we are talking about occurs within the modern era. The term instantly distinguishes it from past ice age cycles etc. 01:58, 14 October 2021 (UTC)

Just checked what AR6, SPM pp.5-9 says, and unfortunately I think the end of the last sentence overstates what’s in the latest report. I would suggest changing the wording from “Earths history” to “the past several thousand years.” Dtetta (talk) 05:50, 10 October 2021 (UTC)

Also recommend those AR6 pages, and this NY times story on the report, as the two citations at the end of the sentence. The Times story includes coverage of the historical perspective from the report. Dtetta (talk) 06:23, 10 October 2021 (UTC)

The sentence is based on the following SR15: "These global-level rates of human-driven change far exceed the rates of change driven by geophysical or biosphere forces that have altered the Earth System trajectory in the past (e.g., Summerhayes, 2015; Foster et al., 2017); even abrupt geophysical events do not approach current rates of human-driven change". I think it supports the sentence. I propose one tweak to be closer to SR15 and AR6.

The problem with saying "over the last few thousands years" is that readers may think that changes did happen more rapidly before, even though there is no evidence for this. With the word "known", we take care of this ambiguity of not knowing the full history of the Earth's climate.

There have been previous periods of climate change, but the current changes are more rapid than any known events in Earth's history.

Femke (talk) 09:54, 10 October 2021 (UTC)

Great - yes, I see that at Ch1, p54. I’ll use that cite (and quote) rather than AR6. Makes me very uncomfortable, though, that AR6 is so decidedly less emphatic (both in the SPM and the TS) about the unprecedented nature of the current rate of change. Would have thought that the NY Times would have created a similarly strong historical comparison in their story if they thought it was supported by AR6, but they didn’t. Concerned that if I include the AR6 SPM pages in the citation, an observant reader would see a discrepancy. And this is a very important statement in the article. Thoughts? Just use the SR15 citation only? Dtetta (talk) 14:04, 10 October 2021 (UTC)

If we go for this, we should include only SR15. AR6 expresses more certainty that drivers (which could be included in changes rather than warming) are unprecedented, and that ocean warming is unprecedented. I think AR6 is relying on more direct evidence, while the statement of SR15 statement also includes evidence of drivers of change + physical understanding. I understand your worry, and will object only weakly to having a statement with something like 'thousands of years'. Femke (talk) 14:40, 10 October 2021 (UTC)

Actually I like your phrasing, and would prefer to use that. Just concerned that it’s not supported well by AR6. It sounds lie you don’t see that as a significant issue, in terms of sourcing, correct? Dtetta (talk) 15:37, 10 October 2021 (UTC)

That's right. SR15 is still quite recent, and AR6 does not contradict it imo, it just focuses on individual changes separately. Femke (talk) 15:40, 10 October 2021 (UTC)

OK - Wiil make the edit with the SP15 citation and quote. Dtetta (talk) 17:22, 10 October 2021 (UTC)

I've been away and haven't read all the points and proposals. But I quite like the current wording.Bogazicili (talk) 23:02, 10 October 2021 (UTC)

Discussion second paragraph

I don't have a strong opinion on the first paragraph, other than agreeing that "on ecosystems" is incorrect. Regarding the second paragraph, the new wording mixes up the sources of emissions a bit. Starting from biggest sources of emissions to smallest, the order is 1) fossil fuel burning, 2) agriculture, 3) deforestation, and 4) chemical reactions in certain industrial processes.[2] Where people often get mixed up is that steel-making and cement-making involve both fossil fuel burning and CO2-generating chemical reactions.

Some types of climate change can even can act as a feedback mechanism also doesn't quite make sense. There aren't different types of climate change. There is more than one possible feedback mechanism. Perhaps "There are different ways that the effects of climate change can generate feedback loops that further accelerate climate change" would be more accurate? Clayoquot (talk | contribs) 04:57, 5 October 2021 (UTC)

How about: Some climate changes feedback, either speeding up or slowing down global warming.? Chidgk1 (talk) 08:04, 5 October 2021 (UTC)

I agree with Clayoquot for a couple of reasons: the words "feedback mechanism" are quite odd, scientific literature uses the standalone noun feedback, scicomm typically uses feedback loop. I also think we should tell what is actually happening (the feedbacks amplify global warming), rather than what individual feedbacks may do (most amplify, some dampen). The wording "either speeding up or slowing down" can be interpreted as "we don't know what the net feedback effect is", which is a climate denialist talking point. I can't think of an accurate but simple synonym for amplify, so will compromise at accelerate/speed up which is less informative (amplify gives a different end point to accelerate). To shorten Clayoquots sentence: The effects of global warming generate feedback loops that accelerate warming. FemkeMilene (talk) 08:21, 5 October 2021 (UTC)

Have not checked but I suspect "amplify" may be the same readability as "accelerate". But you don't like "feedback" as a verb Femke? How about Some climate changes feedback, amplifying global warming.?

That really doesn't work for me. It's such a deviation from how that word is typically used, that read changes as the verb initially. 08:42, 5 October 2021 (UTC)

Most climate change feedback amplifies global warming. or Climate feedbacks are speeding up global warming.? If not maybe we should stick with the existing single sentence rather than splitting in two? Chidgk1 (talk) 09:06, 5 October 2021 (UTC)

I'm okay with sticking to one sentence if we can cut back on words in the example clause. The two-sentence proposal does not make clear it's dealing with examples. Dtetta cut out the largest feedback (water vapour), and we also do not mention the second-largest feedback (clouds), but I'm fine with that. I think it's a good idea not to mention the word sink in the lede, as it's jargon. However, 'absorb back' implies it was in the ocean/biosphere before, rather than in geological deposits. What about Temperature rise is amplified by climate feedbacks, such as loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself) and changes to land and ocean carbon sinks release of methane from permafrost. FemkeMilene (talk) 10:42, 5 October 2021 (UTC)

Fine by me Chidgk1 (talk) 10:57, 5 October 2021 (UTC)

Love it. Clayoquot (talk | contribs) 13:59, 5 October 2021 (UTC)

@Clayoquot:: How about Burning oil to move vehicles, and coal and gas to make heat and electricity, emits most as carbon dioxide. Agriculture and forest loss are also significant sources of greenhouse gas; as are chemical reactions making cement and steel. Chidgk1 (talk) 09:46, 5 October 2021 (UTC)

Chidgk1, Your second sentence looks great to me. The first sentence is a bit of an oversimplification (e.g. oil derivatives are also used for heating and electricity generation). I can't parse emits most as carbon dioxide. Clayoquot (talk | contribs) 16:59, 5 October 2021 (UTC)

Glad to see the discussion on how the last two sentences can be further improved. I’m happy to let Clayoquot, Femke, and Chidgk1, figure out the most appropriate wording. My only suggestion is you take the current proposed paragraph, and run your changes through the readable site, and notice the difference your rewording has on the grade level and reading ease scores. Guessing, as Clayoquot has noted, that most of these further changes won’t have a significant impact, but it’s worth checking out. Pretty sure you can do that without a subscription prompt from them as long as you’re not trying to get reports. You’ll see what I mean once you try it.

Also want to briefly touch on the issue Clayoquot has brought up regarding the ordering of the GHG sources. I did intentionally change the order a bit. In this case I went for grouping things that were similar in nature, rather a ranked order of level of emissions (although I do think Our World In Data does a great job on their site). I did that in part to help the reader distinguish ag and forestry as different kinds of GHG sources. IPCC does a pretty good job of capturing the dual role of these sectors as both sinks and sources in Chapter 2, section 2.3 of the SRCCL report. I did not want to get into detail in this overview paragraph, but I thought that separation was a useful one.

The idea of listing by order of emissions makes some sense. However if we really want to have that as a hard criteria, we need to reconcile it with the sentence in the article itself dealing with significant sources on a production basis, which I wrote a while back using EPA 2019 as a reference. That provides a similar but not quite same list. We could also rank sources from a consumption basis, which was an earlier sentence in that section. So there are a few different ways of ordering these sources that are probably equally valid. I like keeping ag and forestry separate for the reasons I’ve described above, and the text in this case also uses two sentences rather than one (a readability improvement). But I’m also ok with a different way of ordering these sources. Dtetta (talk) 14:45, 5 October 2021 (UTC)

I'm okay with the different order, but the first sentence contains a minor inaccuracy. It states that fossil fuel burning is done for energy use and cement production. However, the fossil burning for cements emissions is the for energy, whereas the other 60% is chemical and does not depend on fossil fuels.

I like your comment because it’s an interesting example of readability and understanding, even in with what appears to be straightforward text. When I read that sentence, I think of fossil fuel burning for energy use as one category, and then GHG emissions from steel and cement as entirely separate categories in their own right. The paragraph I wrote on these sources in the mitigation section in fact talks about the need to decarbonize these production processes. So I was well aware of the nuance you bring up when I wrote the sentence, but nevertheless I thought that I was talking about GHG emissions from steel and cement in their entirety, and did not see any contradiction. In that sense I am glossing over the issue of fossil fuels vs the chemical processes themselves for steel and cement, but to me that’s ok for an overview type of summary in the lede, and I don’t think it’s incorrect. I sill like the way I have proposed it in general, and I’d suggest we try to avoid reading too much into these sentences with an expert’s eye, but rather think about how an average reader might understand them. Dtetta (talk) 19:31, 5 October 2021 (UTC)

On a seperate note, I am happy with deleting the sentence on consensus, which came over as defensive. We will need to write something about the society section in the lede, and I think the misinformation and protest could be fitted in the last paragraph. FemkeMilene (talk) 15:44, 5 October 2021 (UTC)

When it comes to GHG sources, we're digressing a bit from readability so perhaps this should be a different Talk page section, but to continue here for now: I agree the lead and the body should be consistent in how they classify sources of emissions. We should pick one framework for classifying emissions and use it consistently as the primary one. Then if we feel a need to present alternative ways of classifying emissions we should tell the reader that we're switching frameworks.

We currently use three frameworks for classifying sources of emissions:

1. The lead uses the World Resources Institute framework, which OWID uses here, which says energy is 73% of emissions, AFOLU is 18%, etc.
2. The Climate change#Greenhouse gases section starts out by grouping things by greenhouse gas type (all CO2 emissions followed by all methane emissions and then all nitrous oxide emissions).
3. The Climate change#Greenhouse gases then states "From a production standpoint, the primary sources of global greenhouse gas emissions are estimated as: electricity and heat (25%), agriculture and forestry (24%), industry and manufacturing (21%), transport (14%), and buildings (6%).", which reflects EPA 2019.

I'm confused by why we use framework #2 at all. What other publications organize emissions this way, and why is it more helpful than framework #1 or #3? If think framework #1 is by far the most informative in terms of informing the general reader about mitigation strategies. Framework #3 obscures the importance of the electricity sector (by combining it with heat) and obscures the importance of energy generally. Clayoquot (talk | contribs) 17:44, 5 October 2021 (UTC)]

I would support using the WRI/OWID framework as a general rule, both in this paragraph and in the Drivers of recent temperature rise section. The one caveat for me is that we should highlight the dual role that ag and forestry play as both sinks and sources of GHGs, which again is why I listed them separately. And, of course, we should avoid long lists with poor readabililty, which is why I made my edit to that sentence in the first place. Dtetta (talk) 19:50, 5 October 2021 (UTC)

Great. As for highlighting the dual role of agriculture and forestry as both sources and sinks for carbon, I did not understand that that was what the revised second paragraph was saying. Is the part about what "the land and oceans can absorb back" referring to the carbon sequestered by trees and soils? Clayoquot (talk | contribs) 04:33, 6 October 2021 (UTC)

So yes, I was trying to do that in two spots in the paragraph; one by distinguishing them as sources via a separate sentence, and then in that “absorb back” phrase you are referring to. Probably better ways of doing this, but that was my initial attempt at it. Dtetta (talk) 12:26, 6 October 2021 (UTC)

The fact that trees, soils, etc. act as carbon sinks should be stated separately from the fact that loss of these sinks is involved in feedback loops. Also, calling trees, plants, roots, soils, seaweed, etc. "land and oceans" is jargon. The general reader thinks that land is the hard stuff under our feet and that oceans are made up of salt water. Clayoquot (talk | contribs) 20:40, 6 October 2021 (UTC)

I never thought about it like that, but you're right. It's not only the word sink that is jargon. Femke (talk) 09:16, 7 October 2021 (UTC)

So at this point, with Femke’s edit of the first sentence, I would suggest we focus on two things for the rest of the paragraph. A couple of sentences on sources. Here there seems to be some support for the WRI/OWID framework for describing them. And then a couple of sentences on feedback, including ways in which it can increase or decrease the rate of future warming. It sounds like we can eliminate the sentence on scientific consensus, at least in this paragraph (although it may still be worth including somewhere in the lead). Dtetta (talk) 12:37, 6 October 2021 (UTC)

And thanks for hanging in there with this process! I do think we’ll end up with paragraphs that are easier for most readers to understand:) Dtetta (talk) 13:46, 6 October 2021 (UTC)

So here is my proposal for the sentences on sources, based largely on the WRI/OWID characterization of this:” Burning fossil fuels for energy use in industry, transportation, and buildings creates most of these emissions. Agriculture practices, steel making, cement production, and forest loss are also significant sources.” On readable.com the reading grade level for this paragraph drops abut 2 grade levels, and reading ease increases about 8 points, from just this change to what’s currently in the paragraph. Dtetta (talk) 14:49, 6 October 2021 (UTC)

Those sentences feel perfectly natural. We can even simplify by dropping the word practices. FemkeMilene (talk) 17:34, 6 October 2021 (UTC)

I like it too. I agree with Femke on dropping practices and also suggest dropping " use in industry, transportation, and buildings". Clayoquot (talk | contribs) 18:41, 6 October 2021 (UTC)

That sentence has the advantage of being simpler, but personally I like having specific examples, especially if we can later make them jibe with how they are described in the Drivers of recent temperature rise section. I’m ok with the shorter version, though. - Other thoughts? Dtetta (talk) 15:37, 7 October 2021 (UTC)

I think "energy" is such a widely understood concept that examples are not needed. And actually the term "buildings" is jargon in this context. Most people do not understand that the making of the cement and steel in buildings is not "buildings", but the emissions caused by mining cryptocurrency are "buildings". Clayoquot (talk | contribs) 17:17, 7 October 2021 (UTC)

While the discussion on the “sources” sentence still gets resolved, here is the current final sentence on feedbacks and examples: “Temperature rise can be amplified by climate feedbacks, such as the loss of sunlight-reflecting snow cover, or limits to land and ocean carbon sinks.”

Just wanting to see if there are other comments on this latest version. It’s clearly a readability improvement. My only strong suggestion is that “land and carbon sinks” is still technical/jargony. Perhaps something like :”how much greenhouse gases forests, soils and oceans can absorb.” I would also prefer that the text clearly state that “future warming can be increased or decreased”, my thought is that we should not modify our best attempt at a scientific summary based on concerns with denialism, which we are in effect doing by limiting the the phrase to just “can amplify feedbacks” but I suspect I am in the minority here. Other general thoughts on the current sentence, particularly on the “land and ocean carbon sinks” phrase? Dtetta (talk) 15:44, 7 October 2021 (UTC)

I think both the phrasing "can amplify" and "increased or decreased" imply that feedbacks could decrease the direct effect of CO₂, which is not the case (net). I see both sentences as ambiguous (net or individual feedbacks), and if only to avoid ambiguity, we should not write the sentence like that. I think the wording "Temperature is amplified" takes away that ambiguity, describing what is happening now.

I believe "how much CO₂ forest, soils and oceans absorb" (without can), is an improvement on the current text, but it does not explain how it is a feedback (rather than the reference absorption of like 50% of emitted CO₂) Maybe "changes in how much CO₂ forests, soils and oceans absorb". That may lengthen the sentence too much. I have a weak preference for giving an example instead. Permafrost, or forests losing carbon due to drought, are both big feedbacks and easy to understand, happy with either of them. Femke (talk) 16:17, 7 October 2021 (UTC)

I like the first 2/3 of this sentence. I would replace "land and ocean carbon sinks" by a specific example like "deforestation caused by drought". Concrete examples are much easier to understand. Clayoquot (talk | contribs) 17:03, 7 October 2021 (UTC)

Re: a feedback that can decrease the direct effect of increased CO2 - AR6 page TS-47: “Since the 1980s, carbon fertilization from rising atmospheric CO2 has increased the strength of the net land CO2 sink (medium confidence).”, For that reason I still prefer Efrazil’s edit that changed the phrase to “can amplify”, although I realize that the over exaggeration of this effect is a CC denialist trope. I like Femke’s “changes in how much…” rephrasing, and I think the inclusion of forests, soils and oceans in the phrase is reasonably specific. Dtetta (talk) 19:50, 7 October 2021 (UTC)

And I can name quite a few more negative feedbacks, it's what I did my PhD on :) . The net effect is amplifying, and the word 'can' implies doubt. Can we rephrase in such a way that this sentence loses its ambiguity? That it's clear whether we're taking about the individual feedbacks or the net effect? Femke (talk) 20:10, 7 October 2021 (UTC)

OK - I see where on p.TS-59 it states:”The combined effect of all climate feedback processes is to amplify the climate response to forcing.” This amplification effect seems to be mainly due to clouds and increased water vapour. However, on page 46 “ Projections show that while land and ocean sinks absorb more CO2 under high emissions scenarios than low emissions scenarios, the fraction of emissions removed from the atmosphere by natural sinks decreases with higher concentrations (high confidence).” So there are also significant negative feedbacks.

Given this, how about “Some climate changes (and impacts) cause the rate of global warming to increase more rapidly. Increased water vapour in the atmosphere, or the loss of snow cover, has this effect. In contrast, CO2 absorption by forests and other vegetation can moderate these increases, to some extent.” Grade level 9.6, Reading ease 53 for those three sentences, compared to scores of 12.6 and 49 for the current last sentence. I think the term feedbacks, and the overall net positive concept, can be described better in the main part of the article. Dtetta (talk) 05:11, 8 October 2021 (UTC)

If folks think it’s truly important to have the “feedbacks” term in the sentence, we could also do that parenthetically: Some climate change and impacts (called feedbacks)…. Dtetta (talk) 13:50, 8 October 2021 (UTC)

(edit conflict) I like the creative juices here and I think a sentence without the word feedback can work. I'm not happy with prose quality yet, but that's not my strong suit really. A few thoughts

• You're proposing to have a sentence about feedbacks and contrasting that to a sentence about vegetation sinks. You're not talking about how global warming would change those carbon sinks (amplify GW) or how higher CO₂ concentrations change those sinks (reduce GW, the two together slightly amplify). So you're not talking about a feedback here. I think we need to be consistent, even if we omit the word feedback.
• I think the structure "cause ... to" is complex, and prefer a more active word order "global warming is sped up by".
• I really liked your previous proposal of leaving out water vapour, because it's not clear to a lay reader why water vapour would do this, and bracketed explanations make sentences longer.
• these increases -> warming. Vegetation -> plants.

To keep it simple, I would still want to describe the collective effect of feedbacks (CO2-carbon cycle + climate-carbon cycle + climate-radiative forcing), but coming up blank how to do it. I struggle to find a alternative good solution, having to kill my darling. I feel strongly that the proposed text is too long, and puts undue attention on feedbacks. Femke (talk) 14:13, 8 October 2021 (UTC)

This should work! "Temperature rise is affected by climate feedbacks, such as the loss of sunlight-reflecting snow cover and the release of carbon dioxide after forest droughts. Collectively, they amplify global warming." Femke (talk) 14:18, 8 October 2021 (UTC)

I like that - nice work! I think you mean “Temperature rise is affected…” Dtetta (talk) 14:37, 8 October 2021 (UTC)

I would note that changing “amplify” to “increase the rate of” creates a significant improvement in readability. Changing”Temperature rise is” to “Warming is also” improves readability, but to a lesser extent. The use of “also” helps with the transition from two different concepts in the same paragraph - talking about sources of warming, then talking about temperature rise impacts from feedbacks. Dtetta (talk) 15:12, 8 October 2021 (UTC)

I like it too. Clayoquot (talk | contribs) 02:55, 9 October 2021 (UTC)

Here is a proposed second paragraph based on our discussion to date. I’m using the first sentence that Femke recently posted from my original proposal, with a slight change to avoid using the word “main(ly)” twice. I believe the second sentence reflects the discussion we’ve had, in particular Femke’s and Clayoquot‘s comments. The last two sentences are Femke‘s recent proposal, with a minor change from “they” to “these” in the last sentence. Grade level of 10.7 and reading ease of 43.5 for this paragraph, compared to scores of 15.5 and 32 for what was there last week before we started this work. Changing “amplify” to “increases the rate of” would further reduce the grade level down to 10.4, and increase the reading ease score to 46.6, but I didn’t see strong support for that, so I didn’t include it in this proposal. The “Temperature rise…” sentence is still fairly difficult in terms of readability, but we’ve made some big improvements. Dtetta (talk) 05:53, 10 October 2021 (UTC)

The main cause of these changes is the emission of greenhouse gases, mostly carbon dioxide (CO2) and methane. Burning fossil fuels for energy use creates most of these emissions. Agriculture, steel making, cement production, and forest loss are also significant sources. Temperature rise is affected by climate feedbacks, such as the loss of sunlight-reflecting snow cover and the release of carbon dioxide after forest droughts. Collectively, these amplify global warming.

I think that works really well and is ready to go into the article. One suggestion to take or leave - I'd change "after forest droughts" to "from drought-stricken forests". Thanks for your hard work on this! P.S. I might disappear from this discussion for a while to catch up on other stuff. Clayoquot (talk | contribs) 04:54, 10 October 2021 (UTC)

I like that suggestion, and it’s a slight improvement in readability. Dtetta (talk) 13:56, 11 October 2021 (UTC)

I like it. One more tweak? "Of these changes" and "of these emissions" feels a bit repetitive. Can we omit the first? I think it's clear from context that we're talking about climate change. Femke (talk) 09:57, 10 October 2021 (UTC)

I would suggest we just eliminate “of these changes” to address that repetitive phrasing, particularly if we are going to combine the paragraphs. Dtetta (talk) 13:41, 11 October 2021 (UTC)

I think we should maintain the current sentence about consensus: "The human cause of climate change is not disputed by any scientific body of national or international standing.[5]" I don't think it comes as defensive. NASA's climate change website is one of the most popular about this subject, and this issue is one of the top 3 questions in FAQ page. ("Do scientists agree on climate change?" [3]). So I still think this is relevant in the lead. Current wording also does a good job of summarizing the "Scientific consensus and society" section. Bogazicili (talk) 23:08, 10 October 2021 (UTC)

Their prose does not mention it explicitly however. Our FAQ mentions it as well. NASA is probably not representative, given the fact that the US has one of the highest levels of climate denial. The Met Office does not mention consensus in their article. I think we should include the protests and maybe misinformation in the last lead paragraph instead. Femke (talk) 07:48, 11 October 2021 (UTC)

Femkemilene, it's not just a US issue. There seems to be a lack of awareness in Europe too [4] Bogazicili (talk) 21:58, 13 October 2021 (UTC)

So I modified the second paragraph, adding Clayoquot’s suggestion and my attempt at responding to Femke’s suggestion on redundancy. I added the words “as well” following climate feedbacks, as I thought that helped with the transitional nature of those last two sentences. Grade level of 10.2 and reading ease of about 50 for these two paragraphs (and changing "amplify" to"increase the rate of" would be a further readability improvement). Didn't merge the paragraphs - thought there might be further discussion on that. IMO Bogazicili’s suggestion may be worth pursuing with a much simpler type of statement, just not sure where that would go now. Dtetta (talk) 18:41, 11 October 2021 (UTC)

I am not sure there was explicit consensus for removing the part about scientific consensus. Only Femkemilene said they are ok with it. I'm thinking about reinserting this into last paragraph if and until a replacement is found. Bogazicili (talk) 22:00, 13 October 2021 (UTC)

Merging the paragraphs?

Now that we've shortened both paragraphs, I think they can be merged. Four paragraphs in the lede is the max in the manual of style, so would be nice if we will have achieved that too :). Femke (talk) 11:07, 10 October 2021 (UTC)

When I see those two paragraphs together, it seems to work as a decent summary of the first four sections of the article. Dtetta (talk) 06:45, 11 October 2021 (UTC)

About procedure

Hi folks, one other item. I’m glad people are interested in making edits to improve readability. But I think it will be better if we can keep up our past practice of posting proposed changes on the talk page first. I would suggest that if you have a specific change in mind, you post it here (or in the first paragraph section of this discussion), along with a brief statement as to how it’s an improvement, and then we can review them as a set and someone can post a revised paragraph in full. This will also help ensure that we are making readability improvements as we do these edits. Doing this piecemeal is getting confusing, at least from my perspective. Dtetta (talk) 01:33, 6 October 2021 (UTC)

That's mainly my fault, sorry. Editing from phone makes it difficult to post the entire paragraph over and over again, but I will stop implementing partial consensus into the article. I think going line-by-line is necessary for the first two paragraphs, but will be less needed when we continue. FemkeMilene (talk) 07:33, 6 October 2021 (UTC)

General discussion

I think overall the new version is easier to understand, and the gain in readability can probably be preserved even after we reword things to make them more accurate. Per WP:PRONOUNS, we should avoid the use of first person, e.g. on our climate. Clayoquot (talk | contribs) 04:57, 5 October 2021 (UTC)

• Support Great work. All of the above versions are so much better than the current text that something should be put in straight away and then further improvements discussed. Chidgk1 (talk) 06:37, 5 October 2021 (UTC)
• Support This is more needed that I realised. The http://www.readabilityofwikipedia.com/ gives us a reading score of 37 for the overall article. Ideally, you want to be above 60 for web content. I'm noticing reading gets more difficult when it's below 50 in a topic I'm not familiar with (I was reviewing Turtle at FAC, and that came out at 49, and I found that difficult). We've probably ended up with complicated sentences as we have had to compromise. Femke (talk) 16:22, 8 October 2021 (UTC)

  I've been going over 1/3(?) of the article for low-hanging fruit in terms of shortening or splitting sentences. This exercise has brought the reading score to a whopping 37. No change. Femke (talk) 18:07, 8 October 2021 (UTC)

  One of those days ;) Well, if we're going to be stuck somewhere, 37 is a place with good company. And we get paid regardless of what the score is, right? Oh wait... Clayoquot (talk | contribs) 02:59, 9 October 2021 (UTC)

It is challenging, but my experience with the first two paragraphs has me fairly convinced we can make significant improvements. Flawed as they might be, the original revisions I posted showed the the Flesch-Kincaid Grade level going down from about 15 to about 10, and the reading ease score from 35 to 54, compared to the original content. I think a grade level of around 10, and a reading ease of in the 50-55 range, is achievable. And you all have made significant contributions towards that:)

And I would strongly advise against doing checks that are based on just URLs. I found that to be a big problem with most of the tools I’ve used so far. Not sure, Femke, if that is what you were doing with the comparison you’ve just described. IMO you really have to be evaluating a specific piece of text to get meaningful results. I took all the lead paragraphs, deleted the citations, and then ran them through readable.com to get my initial baseline data. Plus, using text based entry tools (readable.com or hemingwayapp.com) gives you a much better feel for the process itself - you can see in real time the effect of making sentences shorter, or choosing simpler words, and easily play with alternative phrasing. Dtetta (talk) 04:02, 9 October 2021 (UTC)

I think you're right that "my website" is not to be trusted; it's still stuck at 37 even though I've split and shortened loads of sentences. It gives a wrong word total. Using Word, I do see improvement in some of the sections I've worked on. Femke (talk) 10:47, 9 October 2021 (UTC)

Had a conversation Professor Bruine de Bruin, who authored the study on climate change terminology that’s referenced at the start of this post. She had some ideas for making webpages, including climate change articles, more readable. In addition to the kind of guidance you get from the readability apps, her main suggestion is to try to minimize the number of 3+ syllable words. It’s not so much of an issue with commonly used words, like “temperature”, but it creates problems with words that aren’t familiar to the average reader, like “reforestation”. Dtetta (talk) 20:40, 13 October 2021 (UTC)

Yeah, that works. The total score is now 40 (I think the app misses the first 3000 words, explaining why it didn't change before). A lot of these long 3+ syllable words are nouns in summations (X includes Y and Z). I'm trying to explain Y and Z instead. I think I've now put about 1/3 of the entire article through Hemingway. There are a couple of sections I'm barely touching yet as they've been subject to elaborate discussions. Looking forward to tackling the rest of the lede. Femke (talk) 09:40, 16 October 2021 (UTC)

Emission scenarios and their plausability

Various Representative Concentration Pathways (RCPs) can be used as input for climate models: "a stringent mitigation scenario (RCP2.6), two intermediate scenarios (RCP4.5 and RCP6.0) and one scenario with very high [greenhouse gas] emissions (RCP8.5)".

I am fine with calling RCP2.6 (and RCP1.9) a stringent emission scenario. I do also follow Hausfahter & Peters that the RCP4.5 is the most probable one, with no climate policies installed meaning a global CO2 price of zero, see also Are there enough fossil fuels to generate the IPCC CO2 baseline scenario?, page 5. But RCP6.0, RCP7.0 and RCP8.5 are highly unlikely, on the simple reason that the fossil fuel reserves are not sufficient. Please have a look at the BGR Energy Study 2019, Table 4. --Gunnar (talk) 14:53, 30 September 2021 (UTC)

So are you suggesting a change to "two stringent mitigation scenarios (RCP1.9 and RCP2.6), one intermediate scenario (RCP4.5) and three scenarios with high [greenhouse gas] emissions (RCP6.0, RCP7.0 and RCP8.5)" or maybe better to shorten - how about "ranging from RCP1.9 (Extinction Rebellion has taken control) to RCP8.5 (petrostates sold all their oil cheap and now the permafrost has melted)" :-) Chidgk1 (talk) 15:34, 30 September 2021 (UTC)

Yes, although the unlikely "there is not enough coal to mine and burn" scenarios are only RCP7.0 and RCP8.5, as 6.0 was dropped in AR6. Regarding your funny cookie remark, I don't know what "Extinction Rebellion" means. Actually, I think the people which drive down the use of fossil fuels by ramping up alternative energy sources quickly avoid a price shock with fossil fuels which is able to tank the global economy again. Thus any support mechanism for electric vehicles and driving them on solar power can be seen as part of the Rimini protocol.

BTW, it is a well known fact that petrostates can't pump so much oil to drive CO2 emissions beyond the RCP4.5 threshold, see [5] or [6]. The only reason for having RCP7.0 and RCP8.5 is the misunderstanding of the term "resource" which is not the same as "reserve" and the history of coal reserves. In general, reserves are those resources which are seen as technically and economically mineable at current prices and current technology. But alone the word "mineable" is a large minefield in interpretation, see Oil constant#Reasons for reserve expansion for the reasons of under reporting and not backdating reserve expansions. Coal is an exception of the rule to use the current conditions as reference. Coal is usually assessed with a fixed pattern, e.g. seams of X cm minimum thickness up to a depth of Y meters. The coal is certainly there, as validated by drilling cores, but it is not mineable as nobody would dig it out for given costs. This leads to a shrinking (reserve collapse) of the numbers which former geologist have found, e.g. US coal reserves have fallen from 3839 Gt in 1913 to 237 Gt in the 2010 WEC survey [7]. Finally, the reduction of coal reserves is still more probable than the expansion of coal reserves. If you believe the in the method of curve fitting and the pattern of the logistic growth with non-renewable resources then current coal reserves must be reduced by about 1/3 to give a better estimate for the ultimate resource recovery (= cumulative production at the end of the cycle). --Gunnar (talk) 22:01, 30 September 2021 (UTC)

The new IPCC Physical Science Basis report no longer uses RCPs at all, and instead just talks about degrees of warming. What would be best is to rewrite the section using the new report as the basis. Efbrazil (talk) 15:51, 30 September 2021 (UTC)

@Efbrazil: Actually, the IPCC still uses RCPs but they are named differently. They added a lot of prosa to the so called Shared Socioeconomic Pathways, but these pathways are irrelevant. Important is the emission pathway, which is in the nomenclature of AR6 the last part of the scenario ID. The scenarios are named as SSPx-y.z and while the SSP number x gives a storyline about how the world may develop, the important feature is the final y.z number which is the radiative forcing at the end of the century - same naming approach as with RCPs. From the perspective of climate policies, the SSP number is irrelevant: if the y.z radiative forcing is targeted (or not) by a bunch of tree huggers, competitive market enthusiast or totalitarian buerocrats, that does not matter for global warming. SSP5-8.5, SSP3-7.0, SSP2-4.5, SSP1-2.6, SSP1-1.9 are basically the same as RCP8.5, RCP7.0, RCP4.5, RCP2.6, RCP1.9 although the last one was invented for the 1,5 °C target and did not exist in AR5, and the former RCP6.0 was shifted to RCP7.0 - who knows why. --Gunnar (talk) 19:09, 30 September 2021 (UTC)

To confuse things more, AR4 used scenarios from the IPCC Special Report on Emission Scenarios (SERS). They then switched to RCPs in AR5, and now SSPs in AR6. I personally think SERS were best, as they focused on emissions instead of concentrations, so they could factor in carbon cycle impacts into models and directly address emission mitigation instead of dancing around the issue. Anyhow, given all the thrash and confusion and the absurdity of the new numbering scheme, I personally think this article should frame scenarios in terms of degrees warming by 2100. Like you said, how we get there matters less than where we end up. Efbrazil (talk) 22:14, 30 September 2021 (UTC)

IPCC SPM WGI SPM, page SPM-16, figure a) Future annual emissions of CO₂ (left) - voila, there are your emission scenarios. The official name is SSP1-2.6 and similar, and these are the IDs used elsewhere in the world. The effective global warming is estimated in the table on page SPM-18. What do you mean by frame? What's with a frameless representation, just showing what the assumption was and what the outcome is? By the way, the 40 SERS scenarios were suffering from the GIGO syndrome - garbarge in, garbage out. All of the scenarios assumed more fossil fuels to be burnt which were available according to ressource specialists. [8] Thus, it is better now to have 2.6 and 1.9 RF scenarios, which are actually hard to reach and need some work to get to, and would not be avoided anyway because the fossil fuels would run out. --Gunnar (talk) 22:55, 30 September 2021 (UTC)

Suggest we get rid of all the RCP numbers from this article and have zero, one or at most 2 of the AR6 names (which can be explained fully in more detailed article(s)). I favour zero if anyone has an idea of how to get the meaning across without them. The whole RCP paragraph is too technical at the moment and needs rewriting or deleting I think. Anyone like to propose new wording here? Chidgk1 (talk) 13:45, 2 October 2021 (UTC)

There are 5 AR6 scenarios, therefore I don't understand what you mean that you favour zero if you don't want to skip the IPCC work as a major part of their reports deal with these scenarios. "In general, no likelihood is attached to the scenarios assessed in this Report." [9] p. 1-109.

Name: expected warming until 2100 @ cumulated CO2 emissions in Gt; probability,

• SSP1-1.9: +1,4 °C @ 3.100; severe GHG emission reduction needed
• SSP1-2.6: +1,8 °C @ 4.000; GHG emission reduction needed
• SSP2-4.5: +2,7 °C @ 6.000; likely
• SSP3-7.0: +3,6 °C @ 8.000; unlikely
• SSP5-8.5: +4,4 °C @ 9.800; highly unlikely

The number at the end is the radiative forcing and these are the official names of the scenarios. I don't understand what you intend by suggesting to get rid of these IDs, the rest of the world will use them. So wikipedia readers should given an interpretation sheet if they want to use the wiki-article to decipher press releases, articles from popular sciences or scientific papers. --Gunnar (talk) 22:11, 2 October 2021 (UTC)

Let's use the IPCC qualitative descriptions (very stringent mitigation to very high emissions), rather than the words SSPx-z.y in the main text. When reporting in SSP5-8.5 we should follow IPCC TS, and indicate in a footnote that this is an unlikely scenario which requires a lot of carbon from carbon feedbacks, rather than only human emissions. As our figures don't use these scenario names, I see no reason to include them anymore. Most popular press will use qualitative descriptions for the scenarios and we're not here for only for the select group of people that access scientific papers. FemkeMilene (talk) 04:39, 3 October 2021 (UTC)

Currently the paragraph reads:

Various Representative Concentration Pathways (RCPs) can be used as input for climate models: "a stringent mitigation scenario (RCP2.6), two intermediate scenarios (RCP4.5 and RCP6.0) and one scenario with very high [greenhouse gas] emissions (RCP8.5)". RCPs only look at concentrations of greenhouse gases, and so do not include the response of the carbon cycle. Climate model projections summarised in the IPCC Fifth Assessment Report indicate that, during the 21st century, the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) in a moderate scenario, or as much as 2.6 to 4.8 °C (4.7 to 8.6 °F) in an extreme scenario, depending on the rate of future greenhouse gas emissions and on climate feedback effects.

How about instead putting something like the following AT THE END of the NEXT PARA:

Climate model projections summarised in the IPCC Sixth Assessment Report indicate that by the late 21st century, compared to 1850–1900, the global surface temperature is very likely to rise 1.0°C to 1.8°C under the very low GHG emissions scenario, 2.1°C to 3.5°C in an intermediate scenario, or 3.3°C to 5.7°C under the very high GHG emissions scenario; also depending on climate feedback.

(cite B.1.1.1 on page 41 of https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf)

If you don't like this please propose your suggested text.Chidgk1 (talk) 08:06, 3 October 2021 (UTC)

Apart from the words further/by the end of the 21 century (the metric is not from now, but from pre-industrial), sounds good. I would still like to add a footnote about the controversy of the highest emission scenario based on the TS. Maybe we can link very low emission scenario to SSP, if its not too much of an WP:EGG FemkeMilene (talk) 08:32, 3 October 2021 (UTC)

Can go in, footnote can be added later (I do hope the IPCC is going to finilise page numbers soon). FemkeMilene (talk) 08:35, 3 October 2021 (UTC)

Changed it above before I saw your comment. Yes footnote and link sound good. Err what is TS? Maybe the 3.3°C to 5.7°C is politically almost impossible without positive climate feedback? Gunnar.Kaestle - if so can you suggest a rewording to emphasize that?

I am having second thoughts now. So if I understand right AR6 is saying that feedbacks are well enough understood now that we are "very likely" to stay under 3.5°C with the intermediate GHG emissions And as Gunnar writes above intermediate is likely - pretty sure we can find a source to say it is with China's recent statements. So maybe simply:

"Climate model projections summarised in the IPCC Sixth Assessment Report indicate that by the late 21st century, compared to 1850–1900, the global surface temperature is very likely to rise 2.1°C to 3.5°C in an intermediate GHG emissions scenario, depending on climate feedback."

(cite B.1.1.1 on page 41 of https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf)

And link "intermediate GHG emissions scenario" to details of SSP2-4.5 to be added to Shared Socioeconomic Pathways. What do you think? Chidgk1 (talk) 09:15, 3 October 2021 (UTC)

I strongly prefer to show a range of scenarios. The IPCC explicitly says that even the 8.5 scenario cannot be excluded with carbon cycle uncertainties. I think it's also very important to show a scenario that may keep us well under 2 degrees. FemkeMilene (talk) 09:21, 3 October 2021 (UTC)

TS is the technical summary of the report. Discussion on page 22. FemkeMilene (talk) 09:37, 3 October 2021 (UTC)

Amended - feel free to improve further anyone Chidgk1 (talk) 10:37, 3 October 2021 (UTC)

Fahrenheit clutter

I'm always thinking of ways to make the article more streamlined without leaving out important information. Per MOS:CONVERSIONS, we're allowed to only convert Celsius to Fahrenheit once (I'd say once in lede and once in body), if we have a footnote explaining the conversion. Given that even US-based media often uses Celsius for the Paris goals, I would like to make that switch. Any objections? FemkeMilene (talk) 09:49, 2 October 2021 (UTC)

Good idea. One or two parenthetic expressions, possibly explaining 1.5°C-->2.7°F, should be enough. —RCraig09 (talk) 11:41, 2 October 2021 (UTC)

Done. FemkeMilene (talk) 10:53, 3 October 2021 (UTC)

First word readability

Suggest "Human-induced" changed to simpler word. How about "Human-made"? Chidgk1 (talk) 07:29, 3 October 2021 (UTC)

I think that's a neologism. While I dislike words that are more associated with one gender than the other, the solution, especially for Wikipedia, is not to use newly invented words.

That said, I hope to explore first sentences like "The burning of fossil fuels and other greenhouse gas emissions are rasing temperatures resulting in large scale shifts in weather patterns", tweaked by our resident prose experts. FemkeMilene (talk) 08:50, 3 October 2021 (UTC)

Re the current first sentence: I disfavor the current "Human-induced climate change includes..." because the phrase sounds like a generic description, implying there might be other epochs in which humans induced substantial climate change. I favor "Modern-era climate change includes..." because that is what consensus decided this article was about during the extended renaming discussions a couple of years ago ^{(distinguished from Climate variability and change)}. Definitely, we should apply "human-caused" to describe "emissions" as humans are a direct cause of the emissions, but not a direct cause of climate change; symbolically:

Humans-->emissions-->GH effect-->Global warming-->Climate change

—RCraig09 (talk) 21:22, 3 October 2021 (UTC)

Since there has been so much debate on this, here are some very accessible sources from NASA:

'“Climate change” encompasses global warming, but refers to the broader range of changes that are happening to our planet. These include rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times. These are all consequences of warming, which is caused mainly by people burning fossil fuels and putting out heat-trapping gases into the air.' [10] [11]

As such, I think human-induced is ok. Bogazicili (talk) 00:32, 4 October 2021 (UTC)

My point was not about the meaning of "induced" but its readability. That is presumably why NASA don't use it in the text you quote. Chidgk1 (talk) 09:52, 5 October 2021 (UTC)

Why not just "Human caused"? Efbrazil (talk) 23:24, 5 October 2021 (UTC)

"Human-caused" is definitely more readable than "Human-induced". Not saying direct or indirect. Can I change that right now? Chidgk1 (talk) 09:55, 6 October 2021 (UTC)

Human-induced sounds significantly better to my ears. I hope this point is moot if my proposal above is improved and accepted. FemkeMilene (talk) 14:19, 6 October 2021 (UTC)

Caused is a much simpler word than induced though- you learn caused in elementary school. Induced is a word that comes along only in advanced high school classes or maybe college or maybe never. Other than to your ears Femkemilene, is there a reason to oppose the change? We can explore first sentence changes after getting rid of induced. Efbrazil (talk) 23:44, 7 October 2021 (UTC)

Forestation

Hi everyone. If you haven't already added Wikipedia:Today's featured article/October 31, 2021 to your watchlists, please consider doing so. Also, there is a discussion on the Talk page about the word "forestation", and it would be great to get thoughts from a wider range of editors there. Cheers, Clayoquot (talk | contribs) 19:23, 3 October 2021 (UTC)

Climate change modelers win Nobel

This phys.org story gives pretty good coverage. Should we put a brief mention of this in the scientific consensus or discovery sections? Dtetta (talk) 14:02, 6 October 2021 (UTC)

I don't think we should. Both of these sections are probably already too long (given their inclusion in lede). I'm really excited about it though :). My PhD built on the work of Hasselmann. FemkeMilene (talk) 14:06, 6 October 2021 (UTC)

Cool! I liked the fact that the committee noted that Arrhenius, in an 1896 paper “ "built the scientific framework central to the atmospheric column models used in successively more complex treatments that have developed since then,". Which is why I thought it might work in the discovery section. But you’re right in that those sections are probably too long already. Dtetta (talk) 14:15, 6 October 2021 (UTC)

Anyone feeling keen could put it in Portal:Climate_change/News Chidgk1 (talk) 17:39, 6 October 2021 (UTC)

Semi-protected edit request on 9 October 2021

Please change "If clouds become more high and thin" to “If clouds become higher and thinner” Kayneshen (talk) 01:03, 9 October 2021 (UTC)

 Done ScottishFinnishRadish (talk) 01:21, 9 October 2021 (UTC)

Question about "opaque"

I am wondering if we can use a different word than "opaque" in this sentence: "However, the atmosphere is relatively opaque to the heat"? I am having trouble understanding it, I feel the need to click through to opaque but am still confused and wonder if there is a simpler word/explanation that could be used instead or in addition? ( = part of the readability improvement work) EMsmile (talk) 04:08, 13 October 2021 (UTC)

Now: "... not transparent ..." to contrast with preceding sentence. —RCraig09 (talk) 04:50, 13 October 2021 (UTC)

Update about readability and scientific consensus in the lead

After a large amount of discussions and changes in the lead, I'm only seeing a minor change in the readability score. Using this website [12], I looked at the August 1st version of the lead [13] and the current version. Flesch Reading Ease score changed from 46.5 to 47.3. Given that this seems to be only a minor increase, I have to question if the changes were indeed intended to improve readability, especially since that important parts of the lead were dropped out such as the scientific consensus. This makes the lead less complete, as nothing about Climate_change#Scientific_consensus_and_society section is mentioned now. A lead that summarizes the article and the topic is a Wikipedia:Featured_article_criteria after all. Bogazicili (talk) 22:18, 13 October 2021 (UTC)

Most of the lede is still to come. We've cut down on words and are moving towards shorter paragraphs, which are readability improvents not captured by our metric.

I think we could maybe add a sentence about the contrast between consensus and awareness to the last paragraph. With that context, there is a reason to include something about consensus. That paragraph is also a bit small. Femke (talk) 23:21, 13 October 2021 (UTC)

That sounds good. However, sometimes our discussions become too long or deadlocked. As I mentioned above [14], I intend to reinsert the following sentence into the last paragraph if and until we agree on a replacement: "The human cause of climate change is not disputed by any scientific body of national or international standing.[5]"

I also think that part was removed without explicit consensus; people mostly seem to have commented on wording improvements etc. Bogazicili (talk) 23:31, 13 October 2021 (UTC)

I don't think that fits in the last paragraph like that. The last paragraph is society and politics, not about science. I would like to defer to the FAR and keep it out for now on NPOV grounds. Femke (talk) 23:47, 13 October 2021 (UTC)

I'm thinking something along the lines of: Public debate about climate change has been strongly affected by misinformation. A large share of the public is unaware of the scientific consensus on its cause. Of course, the body would have to be amended. This would summarise more if the section. Femke (talk) 00:00, 14 October 2021 (UTC)

Mentioned this already, but I’ll repeat it again. I have much different numbers than what Bogazicili states. The first two paragraphs had a grade level of 15 and a reading ease score of 35.6 (per the readable.com scoring reports) when we started this process. When we were done editing them, the grade level had gone down nearly 5 grades, to 10.5, and reading ease score had gone up to 45.3. Major improvements IMO, and they could be higher with a couple of minor tweaks. Happy to provide links again to the specific reports if anyone wants.

I’m ok with adding a sentence on scientific consensus that is in that general readability range. Seems like it might best go at the end of the current second sentence, although I’m not sure if Femke’s particular wording fits with the way the first two paragraphs are worded. I would just suggest something positive, as I had earlier. Something along the lines of “These ideas have near unanimous scientific consensus behind them” after the second sentence. Just a suggestion. I had suggested this earlier, but there did not seem to be support for it, nor was there much objection to eliminating the original sentence that was there. Which is I think how we got to where we are now. Dtetta (talk) 04:07, 15 October 2021 (UTC)

Apologies. I misread the scores for the revised paragraphs - I was just reporting the score for the second paragraph. For the two paragraphs that are now combined as one, it’s a grade level of 10.2 and a reading ease of about 50, an even greater improvement that I stated in my 15 October post. Dtetta (talk) 06:42, 16 October 2021 (UTC)

Maybe it's time for an RfC? I think Dtettas proposal is an improvement, but I still feel its defensive. Femke (talk) 06:51, 15 October 2021 (UTC)

Length of the lead

The lead is currently still on the short side (461 words). I know there's no hard and fast rule for this. I usually work on 600 words as being a good length; 4 full paragraphs. Do I understand right that the plan is to make the fourth paragraph a bit longer still? EMsmile (talk) 02:05, 14 October 2021 (UTC)

In discussions at FAR/WIAFA , we came to the conclusion that 500 words would be the ideal length and that the length was on the long side. 500 words still puts us above the 50-100 per paragraph words recommended for easy writing. The second and third paragraph should be condensed a bit, while the fourth needs an expansion imo. Femke (talk) 06:38, 14 October 2021 (UTC)

Questions about discovery section

I don't understand the full meaning of this sentence: "Changes in the concentrations of these gases could have caused "all the mutations of climate which the researches of geologists reveal" including ice ages." I had interpreted this to mean: "The scientists at that time discovered that changing concentrations of these gases could have caused "all the mutations of climate which the researches of geologists reveal" including ice ages" but apparently not (Femkemilene reverted this). To me it's unclear whether this sentence is about something that was discovered by someone back then. I think it needs a linking with the previous sentence to give it a logical flow. The sentence before that states: "John Tyndall established that nitrogen and oxygen (99% of dry air) are transparent to infrared, but water vapour and traces of some gases (in particular methane and carbon dioxide) both absorb infrared and, when warmed, emit infrared radiation." EMsmile (talk) 02:02, 14 October 2021 (UTC)

I've made the language more friendly to laymen, and based it on language from the Archer et al reference, esp. "MAY HAVE PRODUCED all the mutations...". —RCraig09 (talk) 02:46, 14 October 2021 (UTC)

thanks, your new version is a lot better. "Tyndall conjectured that changes in the concentrations of these gases may have produced all the climate changes that geologists had detected, including ice ages." My only problem is now the word "conjectured". As a fluent, but non native English speaker, I find that word difficult and might be inclined to feel a need to look it up to be sure. Could we replace it? If not, it's also fine, maybe it's just me who's not so familiar with that word. EMsmile (talk) 03:42, 14 October 2021 (UTC)

I debated among "conjecture" and "posited" and "proposed" and "hypothesized"—none of which are very layman-friendly. I think "asserted" is too strong. Someone else may improve on the language, consistent with the source on Google Books. —RCraig09 (talk) 03:48, 14 October 2021 (UTC)

Without having read the Google book, I think "proposed" would be great and easy to understand for the general public. EMsmile (talk) 13:55, 14 October 2021 (UTC)

 Done —RCraig09 (talk) 14:26, 14 October 2021 (UTC)

Ideal length and interlinkage with sub-article

Also, what is the ideal length of this section (given that there is a sub-article). Currently it's 3 paragraphs. Perhaps it's the perfect length. I was just wondering. I am a bit worried that we might be doubling up with work if we work on fine-tuning these sentences when they are perhaps already quite perfect in the lead of History of climate change science (if not, we should update them there accordingly later). Personally, I would be inclined to take an excerpt from the lead of that other article. But I know we don't tend to use excerpts for featured articles. Perhaps we should do it the other way around. Get these three paragraphs perfect, then copy them to the other article to become the other article's lead? That article gets around 400-500 pageviews per day so that's quite a lot. EMsmile (talk) 02:25, 14 October 2021 (UTC)

Question about sentence on congressional hearing

I don't fully understand this sentence: "Scientists alerted the public, and the dangers were highlighted at James Hansen's 1988 Congressional testimony." When did which scientists alert the public? Also, it will be hard to determine a specific date for this as some scientists already spoke about this much earlier, didn't they? So we should perhaps be very specific what we mean here: which scientists alerted which public with which event/publication when? Also it mentions a "Congressional testimony" as if we we were all meant to know what this means. Can we be more specific? I assume it relates to an event in the United States? There could be other congresses, too. Do we have a wikilink for it? EMsmile (talk) 02:37, 14 October 2021 (UTC)

Usage of the words "CO2 concentrations"?

While reviewing the discovery section, I found that we are a bit sloppy with how we refer to CO2 concentrations. I am just wondering if that is on purpose? I would be inclined to consistently speak of CO2 concentrations but perhaps the word "concentration" is regarded as too scientific? Do we prefer "level"? I give some examples how how CO2 is currently included in this section: "warming from increased CO2 would increase the amount of water vapour", "halving of CO2 could have produced the drop in temperature", "expected from doubling CO2 to be around 5-6 °C", "that adding more CO2 would make no difference", "and CO2 levels increasing". EMsmile (talk) 02:19, 14 October 2021 (UTC)

CO2 levels and concentrations are synonyms. Depending on context, the words 'in the atmosphere' can sometimes be omitted. I don't see the problem. Femke (talk) 06:32, 14 October 2021 (UTC)

My problem is with sentences like this "halving of CO2 could have produced the drop in temperature". Shouldn't it be "halving of CO2 concentrations could have produced the drop in temperature"? And instead of "expected from doubling CO2 to be around 5-6 °C" shouldn't it be "expected from doubling CO2 concentrations to be around 5-6 °C"? (or levels if you prefer "level" to concentration). In some cases, it might not be a concentration though but a total mass or "CO2 gas". So just saying CO2 without "level", "ton", "gas" or whatever is inaccurate in my opinion. Using wording such as "the amount of CO2", or "CO2 emissions" would also work in some instances. I just think that CO2 on its own is confusing, and possibly sloppy. (note that from a quick look over the article, for the rest of the article this is done like I suggested; I just noticed it missing in the section on "discovery" (searching with control+F for CO2 doesn't bring up all the instances though, I then looked for CO but this is more time consuming). EMsmile (talk) 10:11, 14 October 2021 (UTC)

Tweaked the text. Femke (talk) 10:22, 14 October 2021 (UTC)

Improving readability of current second paragraph in lede

Readable.com gives this paragraph a grade level of 14.7, and a reading ease of about 28. You can also see, if you paste this paragraph into the Hemingway editor, all the sentences are considered to be simply too long. Not sure if we can easily shorten them all, but here are my suggestions for starting out. I’ve also suggested priority areas for alternative wording.

• Split the first sentence.
• For the second sentence -“Temeraure rise is…” - find simpler wordings for “amplified” and “contributed”.
• Split the third sentence - “Warmer temperatures are”, and find simpler wording for “rates of evaporation”
• Reorganize and simplify the fourth sentence - “Impacts on…”
• Shorten the human impacts sentence - “Climate change threatens…” we don’t need to capture every single one in the lead, IMO. Which are the most important to highlight? Or can they be grouped into more general categories?
• Split the last sentence - “Even if efforts…”.

I will work on this as well, just wanted to post my thoughts on priorities, and see if there are any wording suggestions as I start this. There were lots of great ones for the first two paragraph:) Dtetta (talk) 12:50, 17 October 2021 (UTC)

Here are my proposed changes for this paragraph:

On land, where temperatures have risen about twice as fast as the global average. Deserts are expanding, while and heat waves and wildfires are becoming more common. Temperature rise is amplified Increased warming in the Arctic, where it has contributed to melting permafrost, glacial retreat and sea ice loss. Warmer temperatures are increasing rates of evaporation, also causing more intense storms and other weather extremes. Impacts on ecosystems include the relocation or extinction of many species as their environment changes, most immediately In places like in coral reefs, mountains, and the Arctic, many species are being forced to relocate, or become extinct. Climate change threatens people with food insecurity, and water scarcity, increased flooding, infectious increased and diseases, extreme heat, and economic losses, and displacement. In some cases this may lead to large scale migration. These human impacts have led tThe World Health Organization to is calling climate change the greatest threat to global health in the 21st century. Even if efforts to minimise future warming are successful, some effects will continue for centuries. including These include rising sea levels rise, as well as warmer and more acidic oceans rising ocean temperatures, and ocean acidification.

And this is what it would look like:

On land, temperatures have risen about twice as fast as the global average. Deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing more intense storms and other weather extremes. In places like coral reefs, mountains, and the Arctic, many species are forced to relocate, or become extinct, as their environment changes. Climate change threatens people with food and water scarcity, increased flooding and disease, extreme heat, and economic loss. In some cases this may lead to large scale migration. The World Health Organization is calling climate change the greatest threat to global health in the 21st century. Even if efforts to minimise future warming are successful, some effects will continue for centuries. These include sea level rise, as well as warmer and more acidic oceans.

Grade level of 9.8 and reading ease of 51.5 for this revised paragraph. Dtetta (talk) 04:49, 19 October 2021 (UTC)

And I believe the only significant change in meaning is that I generalized infectious disease to just disease. Dtetta (talk) 04:54, 19 October 2021 (UTC)

I'm mostly happy immediately.

• I'm not that keen on putting more emphasis on migration than other impacts. Maybe we can switch with economic losses? In any case large-scale is not in the body, and the body has specific drivers for displacement, that don't include disease f.i.
• I think 'threatens people' is wording to weasel in that wikilink. Poses risks to is more natural. Femke (talk) 07:27, 19 October 2021 (UTC)

Thanks for the quick response! Glad you generally like it:)

In your first comment, are you saying that creating a second, separate sentence for migration puts more emphasis on it? To me putting the qualifier “in some cases” implies limited applicability, which kind of deemphasizes it - are you concerned that merely breaking it out separately creates an undue emphasis? The end of your first comment also makes me think that the phrase “in some cases” leads you to read that migration is resulting from economic loss specifically, rather than the impacts in general that are listed in the previous sentence. Is that correct? If so, then changing the word “this” to “these impacts” might clarify things. Would that work for you? The body of the article talks about migration “both within and between countries”. I think of that as large scale, but I’m fine with other ways of saying it. Can you propose alternative wording?

I want to push back on “poses risks”. I think that understates the nature of these impacts, and creates the impression for the reader (to the extent that they understand what “poses risks” really means), that we’re talking about theoretical impacts. Many of the impacts mentioned in this sentence are already occurring. I think stronger wording than just “poses risks” is needed. “Threatens people” has a more concrete meaning, IMO, and it’s what’s currently there. However, we do use the word “threat” again in the WHO sentence, so maybe there is another phrase for characterizing/introducing the general nature of these impacts on people, but which better captures their severity. Thoughts from others? Dtetta (talk) 15:18, 19 October 2021 (UTC)

Fair enough on "poses risk"; wouldn't want to change the meaning.

Yes, the extra emphasis was the extra sentence. In a shortened form I'm okay with it.

The problem is that the body gives three reasons for displacement: more frequent extreme weather, sea level rise, and conflict arising from increased competition. The wording in the lede gives more reasons (also, for instance, disease). I don't doubt they may contribute, but we cannot connect these sentences so if we don't do this in the body. What about "It can drive environmental migration", plain and simple. We don't say which of the impacts exactly drive it, and the sentence is almost literally in the body. I've reread the review paper, and cannot really find support for large-scale. As talking about large-scale migration is a scare-mongering technique, I want to stay very close to the HQRS. Femke (talk) 17:16, 19 October 2021 (UTC)

Scientific consensus

There is a new study on the scientific consensus, well published in Environmental Research Letters. Based on the analysis of >88,000 papers, the authors find: "We conclude with high statistical confidence that the scientific consensus on human-caused contemporary climate change—expressed as a proportion of the total publications—exceeds 99% in the peer reviewed scientific literature." This might be interesting for this or other articles. It is my impression that outside of academia the percentage of academic skeptics is usually considerably overestimated. 194.62.169.86 (talk) 06:41, 20 October 2021 (UTC)