Talk:Climate change scenario

Food demand citation
See talk page of economics of global warming – "Food demand citation." Enescot (talk) 13:08, 23 May 2010 (UTC)

Historical Scenarios
Since 1920s, there have been a long and rich history of climate change scenario predictions. Should we add those here or should a new page be made for the history of climate change predictions? I think that would be a quite educational resource to help people learn and avoid the same intellectual pitfalls that have happened in the past. BrainofJT (talk) 16:04, 29 April 2016 (UTC)

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Proposed merge of National climate projections into Climate change scenario
Largely original research, that is not being found or searched for <30 pageviews a month -- either the title of the national article is way off, or it needs to be merged as a section in Climate change scenerios. Sadads (talk) 12:02, 27 February 2021 (UTC)


 * Support merge Topics seem very similar and articles are quite short Chidgk1 (talk) 14:20, 7 March 2021 (UTC)

First sentence needs improving
First sentence does not seem to be right but I am not sure what it should say.

https://www.weforum.org/agenda/2020/09/the-worst-case-climate-change-scenario-could-look-like-this-we-need-to-avert-it/

seems to say that a "climate scenario" is the same as a Representative Concentration Pathway.

Whereas https://cordis.europa.eu/article/id/428611-climate-change-scenario-framework-achievements-and-needs-for-better-future-research

seems to say that they are a combination of RCPs and Shared Socioeconomic Pathways Chidgk1 (talk) 15:18, 14 March 2021 (UTC)


 * Hi User:Chidgk1: has this been addressed in the meantime? Perhaps not. The first sentence is currently this Climate change scenarios (or socioeconomic scenarios or pathways) are projections of future greenhouse gas (GHG) emissions so that scientists can assess future vulnerability to climate change. I've added "or pathways" as a synonym because to me it seems like scenarios and pathways is used to say the same thing. Or maybe I'm wrong? EMsmile (talk) 23:11, 18 March 2024 (UTC)
 * I've changed the first sentence now to A climate change scenario is a hypothetical representation of potential future conditions based on a "consistent set of assumptions about key driving forces" based on the glossary in the AR 6 WG 3 report. I've also tried to explain the difference between scenario and pathway better. EMsmile (talk) 10:38, 19 March 2024 (UTC)
 * Thank you Chidgk1 (talk) 05:11, 20 March 2024 (UTC)

Is the right place to talk about future global temperature scenarios?
I'd like to suggest that this article would be a good place to include some content about future global temperature scenarios, i.e. warming of 2 deg C or 3 deg C etc. I am suggesting this because I have been working on the instrumental temperature record which is about "the past" but I think readers need to be pointed from there to the right place where future global temperature scenarios are explained. So far, I have started a very small summary there and then linked to here but it's not very intuitive so far: https://en.wikipedia.org/wiki/Instrumental_temperature_record#Trends_and_predictions. If not, then which other article is the right place for global temperature trends and predictions? EMsmile (talk) 11:04, 28 March 2022 (UTC)
 * I think this is now obsolete. Those predictions and scenarios are now in climate change mitigation and carbon budget from where I have included excerpts now. EMsmile (talk) 09:39, 20 September 2023 (UTC)

New article on "Existing climate mitigation scenarios perpetuate colonial inequalities"
This article in The Lancet might be worth citing in this article (or at Climate change mitigation and perhaps at Climate justice): "Existing climate mitigation scenarios perpetuate colonial inequalities" (link here). EMsmile (talk) 09:09, 12 July 2022 (UTC)

Overhaul, culling outdated information
I've just done a major overhaul and have culled out some outdated information on future GHG emission from the energy sector. Instead, I have used excerpts to bring some of these predictions back in from other Wikipedia articles. I think this article should be a high level conceptual article to explain to people why scenarios are used, what their limitations are and what the main parameters are that affect those predictions. EMsmile (talk) 09:41, 20 September 2023 (UTC)

Improvements to the readability of the lead
I've just completed a once-over to improve the readability of the lead but I found it hard and didn't manage to improve the score by much. Still lots of sentences are showing up in red when using the readability tool from the list on the right. Needs further work. EMsmile (talk) 23:13, 18 March 2024 (UTC)


 * Thanks! I like some of your changes a lot but for others, I feel that it's losing too much content. Will add some comments in the table above. In general, as this article is not FA, we can pretty much just go ahead with making changes and don't need too much pre-discussion. Although some of your proposed new text I find a bit too radical. ;-) EMsmile (talk) 09:20, 19 March 2024 (UTC)


 * Yes, I have been bold and radical in removing text. Cutting text is surprisingly hard. Adding text back in is easy.
 * So yes, please go for it and implement the changes that you do like. Uwappa (talk) 09:37, 19 March 2024 (UTC)
 * Thanks, I've made those changes now. Just cutting text is easy but I find that the hard part is to convey the same information in a way that is actually understandable for lay persons and non-native English speakers. This is where Chat-GPT can be a great help. - Feel free to tweak and improve further (also the main body of the article), if you have time. EMsmile (talk) 10:51, 19 March 2024 (UTC)
 * Thank you, well done!
 * It did not and still does not feel good to go and change text, knowing we have different ideas. So I prefer to make a quick, way too bold, proposal on the talk page and let you select the improvements that you agree with. Added reply in 3rd column above.
 * I see your enthusiasm about using chat GPT, yet I have my doubts to use it as a fix-it-afterwards tool. I think the WP manual of style should give more guidance. Put editors on the right path from the start: write texts that are easy to read. Basics like the Inverted_pyramid_ and a scannable layout seem unknown to most Wikipedians. I see how some write to impress fellow academics, as if they are still at university. Aiming for easy to read text seems an unknown goal. Weird...
 * Uwappa (talk) 17:25, 19 March 2024 (UTC)
 * I'll take a look but I think for this kind of article (not FA quality, not heavily guarded) it might be more efficient if we make our edits directly in the live article, unless it's really controversial or uncertain or very bold changes.
 * Regarding the important topic of readability, I'll put something on your talk page now so we can discuss it further there. EMsmile (talk) 20:41, 20 March 2024 (UTC)
 * OK, I'll have another look at the text. Feel free to reverse any change you do not like. Uwappa (talk) 23:55, 20 March 2024 (UTC)
 * Did a bit with the text in the lead. Please have a look and reverse what you dislike.
 * I stopped when stumbled upon: national, regional or global scale.
 * I expected the next sentences to detail those 3, but only found detail for 2: countries and global. Text for regions seems to be missing?
 * In addition there it looks like there is an overlap with the chapter Types, but confusing: The chapter types does not detail the types from the lead. Instead it uses different categories. I'll boldly move the last paragraph of the lead to chapter Types so we can deal with both categorisations later, asif they are two axes.

I get stuck in Terminology. The difference between scenario and pathway is unclear to me. Looked at https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6_SYR_LongerReport.pdf#page=29 hoping to find clear definitions and did not find it. Note 102 at the bottom page 29 says scenarios and pathways can be used interchangeably, so why bother about the difference?
 * Bold suggestion: omit the term pathways, just talk about scenarios.
 * Even bolder suggestion: Ditch the whole chapter Terminology as it will be a copy of the lead's first paragraph.

The article is too much at a theoretical level for me. The graph gives hope that the article will provide text about several scenarios, but it hardly does. What I would have expect to find: Uwappa (talk) 12:59, 21 March 2024 (UTC)
 * 1) Where is the text for the scenarios shown in the graph? What are recent scenario's? The graph is based on data from 2015. If population, economy and technology are the main parameters, what are the current trends for those three? What is the most probable scenario based on current knowledge? Are fossil fuels on their way out?
 * 2) What is the worst case scenario? What will happen if CO2 keeps increasing? Will earth head for a Venus type of climate? Will we be cooked? How likely is that?
 * 3) And how about the +2.0C scenario? Is that really so much worse than +1.5C? What will be the difference?
 * 4) What is the scenario for +1.5C? Are we there yet with 2023 at +1.48C? How bad will +1.5C be? What will be the impact on agriculture? Will people be able to grow food at their current location? Are there parts of the world that will become inhabitable due to heat, droughts, floods? Are there other parts of the world where living conditions will improve? How does the good and the bad balance out?
 * 5) What is the best case scenario? What values would the main parameters need to be for that best case scenario? What needs to change to get there?


 * I'm a bit snowed under at the moment and pre-occupied with other articles but I appreciate your interest in this article! I haven't been involved in this article much, just trying to fix it up a bit. But regarding this point of yours: Even bolder suggestion: Ditch the whole chapter Terminology as it will be a copy of the lead's first paragraph.. Here I think you misunderstand what the lead is meant to do. The lead is meant to be a summary of the article. There should be nothing in the lead that isn't also in the main text! So if the main text has a section on terminology then the lead can have a summary about that terminology section (it doesn't have to). So please never remove content from the main text with the justification of "it's already in the lead". EMsmile (talk) 21:21, 21 March 2024 (UTC)
 * And I don't think the purpose of this article is to explain the different temperature scenarios. This can be covered elsewhere, e.g. effects of climate change. I think the purpose of this article is to explain the theory. How do scientists develop scenarios, what parameters are being varied and why. I do think there is a difference between scenario and pathway, and I do think both terms should be explained in this single article (rather than starting a new article specifically on pathways). The pathways are like a roadmap: how do we get from A to B, what do we have to do. There is a timeline with the pathway whereas with scenario there is not. But I agree this is confusing and could be explained better. EMsmile (talk) 21:23, 21 March 2024 (UTC)
 * OK, so it is just theory about scenarios.
 * In that case: what is the graph doing in the lead?
 * Is this understanding correct:
 * a scenario is a possible future, what could the future look like?
 * a pathway is a roadmap, how to reach a particular scenario?
 * Uwappa (talk) 21:31, 21 March 2024 (UTC)
 * Hmm, yes, I do agree that the lead should be a summary and the article text should follow it up with more details. In this case I see a copy of the lead, which does not add much. Uwappa (talk) 21:28, 21 March 2024 (UTC)
 * It also occurred to me just now that the graph is not wonderful for the lead. I think we should move it to the main text. But what kind of other image could we use for the lead? Maybe one that shows the concepts of scenarios and pathways but without giving specific numbers?
 * Yes, I think your description could be right. I'd say a pathway explains how to get to a certain desirable future, e.g. by phasing out fossil fuels in Year X or doing YY in Year ZZZ. But don't take my word for it. Would be good if we find better explanations in some good publications. The IPCC AR6 does give a definition of the two terms but we need to maybe translate that into simpler wording?
 * Regarding In this case I see a copy of the lead, which does not add much. You're right that is not great but I see it as a reminder/placeholder that more detailed about that aspect ought to be added. EMsmile (talk) 21:53, 21 March 2024 (UTC)
 * I don't know where to go with this article.
 * Just theory about scenarios seems a subject for the happy few.
 * Examples of possible futures seems a subject for all humanity.
 * The graph is now stuck in the middle. It shows examples of scenarios, an illustration of theory, yet it does not have good backup by text.
 * I think the pathways are confusing in the lead. When readers arrive at this page to learn more about scenarios, please explain scenarios in the lead and nothing else. Explaining 2 subjects is way more complicated than explaining one. Especially if the second one is not the reason I came to this page but has a confusing overlap. If you want to confuse me, please do so in chapters, don't scare me away in the lead.
 * I'm not sure what to do with the graph. It does show examples of scenario's and what I do like is that is shows multiple scenarios, happily coexisting as multiple possibilities. That clearly distincts scenarios from a prediction of the most likely future. Uwappa (talk) 22:07, 21 March 2024 (UTC)
 * I think the two terms do belong together and they both do deserve to be mentioned in the lead. Especially if scenarios and pathways are used interchangeably in the literature! Compare with carbon offsets and credits which are both explained in one article: carbon offsets and credits. -
 * With regards to content, this content is already (more or less9 covered in other articles, let's not create a duplicate structure. I've just added this to the article:
 * "Predicted trends for greenhouse gas emissions are shown in different formats:
 * Needed emissions cuts
 * Pledges
 * Recent and currently remaining carbon budget"
 * See also the new hatnote that I added. If people want to see details they ought to go to climate change mitigation and effects of climate change. EMsmile (talk) 22:15, 21 March 2024 (UTC)
 * Yes, I think that we need to translate the IPCC definition into something that a larger public can understand. Just quoting the IPCC definition is too much 'mental distance'.
 * I think it would be a good idea to
 * describe scenario and pathway in chapter terminology
 * remove pathway from the lead
 * That way the lead will stay clear and the chapter will provide more detail.
 * I'll boldly go and have a try in terminology. Uwappa (talk) 22:15, 21 March 2024 (UTC)
 * Our comments crossed in cyberspace. I am against dropping "pathways" from the lead (as explained above). I don't think it is that confusing. The people coming to this sub-sub-sub-article (note the low pageviews) are not the general public anyhow. Those will stay at climate change. It's people who want to read in more depth. EMsmile (talk) 22:17, 21 March 2024 (UTC)
 * My advice is also (if you have time): don't just rely on the IPCC definition. Do look around on the internet to find other reliable sources that have explained scenarios and pathways well. - I am signing off from this article for now, will be back for more in the next few days. Happy editing! EMsmile (talk) 22:18, 21 March 2024 (UTC)
 * done, please have a look when you find the time. I am not sure where to go with the references, left them in the source text, but commented them out. Uwappa (talk) 22:28, 21 March 2024 (UTC)
 * I don't understand what you have done here and why you have taken out the ref? It needs to be put back in. If your new text is a true paraphrasing of the IPCC definitions then you need to add that ref back in. If it's not a true paraphrasing but if it's your own interpretation then it is WP:OR and you are actually not allowed to include it.
 * Actually, I don't like the formatting you have used there; note we don't use bolding in the main text, only in the lead. I also think it should be written as prose, like "the definition of scenario is...". EMsmile (talk) 23:31, 21 March 2024 (UTC)
 * Please look again. The ref is still there, but commented out with a question for you. Uwappa (talk) 05:51, 22 March 2024 (UTC)
 * What I have done:
 * I've looked at the IPCC definitions. I think those definitions are jargon for experts, need a translation for WP.
 * I tried to translate the jargon into language for the general public. If you think that is OR, well eh... we better end this cooperation here and now.
 * What I was hoping for: You would fine-tune the definitions where needed. I am willing to help you with text improvements, but am not willing to waste time doing research for terms you seem to be already familiar with.
 * No, I am not going to look around searching for other definitions. I consider the IPCC to be the golden standard. Other definitions will either comply with IPCC and be redundant or contradict and be just confusing.
 * I made the text terminology easy to scan, look like a HTML definition list (dl, dt, dd), typically used for dictionary settings. It is a form-follows-function approach. Make a list of definitions look like... a definition list. Please have a look at the generated HTML, the bold formatting is not mine, it is standard HTML standard Wikipedia CSS for a dt, definition term.
 * The prose versus easy to scan will be a repeating issue. Did you have time yet to look at the 47% improvement of Nielsens Scannable layout example? Do you disagree with Nielsen? Uwappa (talk) 06:34, 22 March 2024 (UTC)
 * I am not sure what the target audience is of this article. So I am a bit lost here.
 * The scientists that create climate change scenarios won't need Wikipedia for their work.
 * the decision makers that use scenarios will hopefully already know what scenarios are and what to use them for.
 * the general audience will be interested in their own, most likely future, but that is not what this article is about.
 * Uwappa (talk) 22:38, 21 March 2024 (UTC)
 * The target audience for all Wikipedia articles is the general public but it can also be non-climate scientists who know nothing about climate change yet. It can also be decision makers. If they are looking for stuff that is not the content of this article then hopefully the hatnote will tell them where to find it. My proposal for a hatnote was "This article is about the theory behind developing and using scenarios. For actual predictions of future emissions and global warming temperatures, see climate change mitigation."
 * Note also a related previous discussion here - a prediction of impacts by degree of warming. https://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Climate_change/Archive_2#Climate_change_degree_by_degree
 * The content about the effects of climate change for different scenarios is actually available in all the other sub-articles. E.g. the article on sea level rise will show different degrees of sea level rise for different emission scenarios.
 * If you think the scope of this article should be different, I suggest you write on the talk page of WikiProject Climate Change to alert more editors to this sub-sub-article (which gets little attention). Personally, I don't think it's a highly important article, actually. (but it should still be improved; e.g. the sections on RCP and SSP do not flow very well) EMsmile (talk) 23:39, 21 March 2024 (UTC)
 * Hmm. No I am not going to start a new WP discussion. Those discussions are very time consuming, usually derail and get lost in details.
 * What I am currently missing at WP climate articles are... pathways related to the tipping points.
 * What needs to be done to stay within +1.5C?
 * What needs to be done to stay within +2.0C?
 * If this article targets the general public and describes pathways, well, seize the opportunity and describe those two important pathways here. The current chapter 'Mitigation scenarios' already touches +1.5C and +2.0C.
 * I think we should both be happy with the chapter terminology before we continue. Could you work on the terminology chapter, improve the definitions? Please add 'Mitigation scenario' to terminology, clear up the difference between pathway and mitigation scenario. Uwappa (talk) 07:09, 22 March 2024 (UTC)
 * How about merging the chapters Terminology and Types into one chapter: Terminology. Uwappa (talk) 07:21, 22 March 2024 (UTC)
 * The long drawn-out WP discussion that you probably refer to is the one on the talk page of climate change (?) But I meant the talk page of WikiProject Climate Change. I've just posted there. My experience is: we're lucky if anyone will react and take the time to join us here for this small sub-article. In most cases, only the main climate change article gets all the attention. So let's see if anyone will join us and help with direction setting.
 * Regarding merging the terminology and types sections: maybe but I am leaning towards keeping them separate and rather fleshing them out more; particularly the one on types.
 * Regarding your point "What needs to be done to stay within +1.5C?" - that's all explained at climate change mitigation, isn't it? Whichever temperature target we have, it's all about mitigation, mitigation, mitigation. EMsmile (talk) 08:48, 22 March 2024 (UTC)
 * I've made some edits to the terminology section. I think it's a good compromise now between the formal wording that the IPCC has adopted and simpler wording that people can understand better. I do think we need both (the formal and the simpler version) because otherwise we would not have a reference that can be cited.
 * I am not sure how to deal with this suggestion of yours: "Please add 'Mitigation scenario' to terminology". This is included under "Types" but not spelled out. If we wanted to spell it out, we could again lean on the text that the IPCC provides in their glossary but I am not sure if this will be very helpful. Again, I think we need to find other publications that we can utilise here, not just the IPCC AR6 report. And just making up our own text is not allowed either as it would be WP:OR. EMsmile (talk) 09:07, 22 March 2024 (UTC)
 * Too many cooks spoil the broth. Attracting other editors seems contra productive to me. My experience: What two people can do in 2 days, will take a group of twenty 20 days, if they succeed at all.
 * I think we should have reached common ground first for the basic issue: Should WP text be tailored for scanning? For me it is hard to ignore Nielsen's test result, 47% improvement.
 * I don't see clear pathways in climate change mitigation for +1.5C and +2.0C. I think there should be so this article can link to them.
 * Please stop accusing me of OR. Pfft, this cooperation is not fun for me anymore. So eh... success and good luck. Uwappa (talk) 09:15, 22 March 2024 (UTC)
 * Sorry, I didn't mean to upset you. I just said that this version doesn't work (for the terminology section) because it has no refs. You had put a hidden comment there that I should put the refs back in but it wasn't clear to me what you meant there.
 * The pathways to +1.5C and +2.0C are essentially the same, and it's more of an academic discussion. We need to reduce GHG emissions and we need to do all the other things that are listed in the mitigation article (e.g. carbon dioxide removal). I don't think there's a need to spell all that out again in this article here. But that's just my opinion. Let's see what others have to say on this topic.
 * And I think more than two editors for any Wikipedia article is a good thing. At least 3 or 4 is ideal. EMsmile (talk) 12:41, 22 March 2024 (UTC)
 * And I think more than two editors for any Wikipedia article is a good thing. At least 3 or 4 is ideal. EMsmile (talk) 12:41, 22 March 2024 (UTC)