Talk:Tipping points in the climate system

Did you know nomination

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by Evrik (talk) 18:58, 30 July 2022 (UTC)

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• Comment or view
• Article history

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• ... that if the Greenland ice sheet passes a tipping point and collapses, this raises the risk that the West Antarctic Ice Sheet collapses too? Source: https://esd.copernicus.org/articles/12/601/2021/
  • ALT1: ... that the Amazon rainforest may change into a savanna once it passes a tipping point? Source: https://www.nature.com/articles/d41586-020-00508-4
  • ALT2: ... that peatland may pass a tipping point due to 'compost-bomb instabililty', releasing large amounts of CO₂ into the atmosphere? Source: https://bsssjournals.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2389.2010.01312.x?saml_referrer
  • Reviewed: Still under 5 noms, so no QPQ needed (this is my third nom..) Femke (talk) 16:50, 27 July 2022 (UTC)
  • Comment:

Improved to Good Article status by Femke (talk). Self-nominated at 16:41, 27 July 2022 (UTC).

• New GA, article is policy compliant, no issues with copyvio or source-text issues in nominator's prior work, hooks are in the article and supported, QPQ not required. Hog Farm _Talk 18:18, 29 July 2022 (UTC)

Remove SCC table?

Given the severe criticism of the study on SCC, I think we should omit the table, and shorten the description of the study. At the moment we decidate much more space to the economists, and only dedicate two line to the response from climate scientists. As such, we give WP:UNDUE attention to one side of the story.

I'm not sure yet how we can further improve the section. Are there secondary sources about this disagreement already? At the moment it's written like "he said, she said", whether ideally we take a more distant view, so that we can write in WP:Wikivoice. Femke (talk) 07:58, 23 October 2022 (UTC)

Very much agree (support).
I'd go slightly further and say we should keep the article as brief as possible and hence remove the content on this study in its entirety.
Alternatively, there could be very brief info on the study and its flaws for which there are also good reasons (e.g. this study getting used and people seeking info on it here).

I removed the table but this was reverted with the rationale "I do disagree with that review; but I think its up to you to prove that the study isn't even worth mentioning", to which I reply:

• if with "disagree with that review" you mean you also think it's low-quality, then why revert the removal – this just causes unnecessary effort and time which is scarce on WP so we should focus on things where we, for often good reasons, disagree
• should I repeat the things in the review to argue for removing this very low-quality and misleading study here? For example, Dietz uncritically reproduced Manne’s assumptions: “The catastrophic warming temperature [of 17.68 ∘C] is derived from the assumption that economic losses rise quadratically, and are calibrated to a loss of 2% at 2.5 ∘C warming or Dietz et al. is also based on papers which are themselves highly questionable. For example, Anthoff et al. (10) concludes that losing the Atlantic Meridional Overturning Circulation (AMOC) would actually increase global GDP. This defies good sense and scientific research predicting a “catastrophic” (6) decline in food production.
• a major issue with that study and what I meant with "it's a misleading approach to evaluate "Impacts" anyway" in my removal-rationale that isn't even mentioned in that linked critical review is that it quantifies the impacts by inappropriate numbers: it does not evaluate risks for (causally contributing to) societal collapse or excess deaths, for number of deaths, for numbers of years of potential life lost (YPLL) and similar, for well-being, for health, and so on. These things should and could be quantified. Various numbers are more appropriate economic measures than GDP or contemporary financial numbers too. There are many flaws with GDP (in relation to reality) and that (these) metric is used in that study without reflection and as if it's some sort of necessity for economics or as if these were natural laws/values that a "science" of economics investigates (this is a common fallacy in economics in general). The issue with that study isn't even Future loss calculations by economists must be developed, not in isolation from climate scientists, but in close collaboration with them. but that economists are unscientifically calculating loss based on historically emerged but highly undue limited constructed measures, the concept of "social cost of carbon" itself is to some degree, at least in its application here, substantially misleading. tl;dr: evaluate the impacts based on things like years of potential life lost (and/or risks thereof), risks and (other) economic costs (monetarily: higher adaptation costs, productivity losses, etc). Not only does the study do a bad job of providing a lower bound of GDP/financial impacts, the metrics/quantifiers used are inappropriate and very narrow anyway. This may also apply to other places in WP where people thought it would be a good idea to put arbitrary "financial price-tags" on things.

Prototyperspective (talk) 11:54, 5 April 2023 (UTC)

Yes I agree with your removal as anyway the table was surely false precision with figures to the nearest US cent Chidgk1 (talk) 15:20, 27 May 2023 (UTC)

Potential content about paper by Will Steffen et al.

This content below was cut out from climate apocalypse, perhaps it could be used here (the paper is already mentioned once):

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A paper published in the journal PNAS in August 2018 entitled "Trajectories of the Earth System in the Anthropocene" described a threshold which, if crossed, could trigger multiple tipping points and self-reinforcing feedback loops that would prevent stabilization of the climate, causing much greater warming and sea-level rises and leading to severe disruption to ecosystems, society, and economies. It described this as the "Hothouse Earth" scenario and proposed a threshold of around 2°C above pre-industrial levels, arguing that decisions taken over the next decade could influence the climate of the planet for tens to hundreds of thousands of years and potentially even lead to conditions which are inhospitable to current human societies. The report also states that there is a possibility of a cascade of tipping points being triggered even if the goal outlined in the Paris Agreement to limit warming to 1.5-2.0°C (2.7-3.6°F) is achieved. EMsmile (talk) 08:35, 23 October 2023 (UTC)

References

EMsmile (talk) 08:35, 23 October 2023 (UTC)

I've added this text block to the section on "potential impacts" but it might require shortening. If someone thinks it doesn't belong there at all, feel free to remove. EMsmile (talk) 11:44, 19 January 2024 (UTC)

Reference errors in Sahel greening section

The excerpt from African humid period has introduced a bunch of ref errors as that article uses the short ref style. Either the sources from that article need to be copied across, or the ref style in the African humid period article needs to be converted to long ref style (at least for that section that is being transcribed. I don't have time at the moment to fix it myself, sorry. EMsmile (talk) 08:38, 23 October 2023 (UTC)

I've removed that excerpt now. It anyway didn't really explain how this Sahel greening aspect is a tipping point in the climate system. If it is important then a paragraph might have to be written from scratch as I don't think this section works as an excerpt: African humid period#Implications for future global warming. Or did I miss or misunderstood something? EMsmile (talk) 22:57, 17 January 2024 (UTC)

@User:InformationToKnowledge: the map in the lead mentions Sahel greening as a tipping point but I don't understand how this fits in with the other tipping points. Isn't it more of a (nice?) effect of changes to precipitation patterns in that region? In which sense is it really a "tipping point"? All the other tipping points are bad/dangerous whereas this one would be good and not dangerous? EMsmile (talk) 09:55, 22 January 2024 (UTC)

You have a point that the excerpt is not great - unlike most of the other tipping point articles, I have never really worked properly on that one, and I'll have to do that eventually.

However, Sahel greening is described not just in the (relatively old) map, but also in the 2022 Science study (the one from which our table is taken) which is the first- or second-most authoritative reference on the subject, so ignoring it is untenable. Ultimately, tipping point refers to a state change in a climate system that is difficult to reverse once it occurs; no more, no less. And it has to be noted that while greater precipitation in Sahel would be good, it has to come from somewhere (besides extra ocean evaporation, that is.) From what I recall, models effectively suggest that the greening of Sahel and the drying of Southern Europe would be two sides of the same coin. InformationToKnowledge (talk) 20:02, 28 January 2024 (UTC)

I see. Can you put it back in then but not with that excerpt, rather with a few sentences (which can be added to later). The excerpt that was there was not clear with regards to how this is a tipping point and why it would be irreversible. EMsmile (talk) 21:16, 28 January 2024 (UTC)

I've removed the excerpt again as I really think it's not helpful. But I have copied across some of the sentences which I think are useful here. Note if you use an excerpt you always have to check the references. In this case, the other article uses short ref style which then results in ref errors (there's a scrip that you can enable to see those harv ref errors more easily but I can't remember now what that script was called; perhaps you have it already).

I've changed the refs to long ref style now. Would be good to add some info from the 2022 Science study. Actually I have added a quote from it now but it would be better to change that into our own words. Overall, the confidence seems rather low so I maintain that this tipping point appears less important/certain than some of the other tipping points, and this should come out clearly. EMsmile (talk) 09:38, 29 January 2024 (UTC)

Proposed change to the structure

I've just changed the structure a bit to make things easier to find. I felt that the section on tipping points was far too long (containing about 70% of the article's content) and the logical sub-structure was missing. The new sub-structure is like this (is that alright?; I've marked in bold my proposed groupings:

Definition
Geological timescales
Comparison of tipping points
Tipping points in the cryosphere
Tipping points in ocean currents
Tipping points in terrestrial systems
Other tipping points
Formerly considered tipping elements
Mathematical theory
Potential impacts

EMsmile (talk) 11:38, 19 January 2024 (UTC)