Template talk:AR6 SSP table

Template-protected edit request on 22 August 2021
In the template in this section:

https://en.wikipedia.org/wiki/IPCC_Sixth_Assessment_Report#Findings

In the SSP1-1.9 the temperature is peaking at 1.6 degrees not 1.5 what can be seen in the sources in the page. Alexander Sauda/אלכסנדר סעודה (talk) 09:46, 22 August 2021 (UTC)
 * Template-protection-unlocked.svg Not done: According to the page's protection level you should be able to edit the page yourself. If you seem to be unable to, please reopen the request with further details. Primefac (talk) 11:15, 22 August 2021 (UTC)
 * Done.--Gunnar (talk) 05:42, 24 August 2021 (UTC)

Likelihood of Reference Scenarios
The full report of IPCC AR6 WG1 on The Physical Science Basis, Chapter 1: Framing, context, and methods, page 1-109 says in paragraph 1.6.1.4: "In general, no likelihood is attached to the scenarios assessed in this Report." - It this also true in particular, meaning that nowhere else in the other AR6 working groups reports this topic will be dealt with?

I'd like to collect literature which give an assessment about the probability of occurrence for the different scenarios. Very prominent is the Nature article of (Hausfather & Peters 2020): "RCP8.5 was intended to explore an unlikely high-risk future. But it has been widely used by some experts, policymakers and the media as something else entirely: as a likely ‘business as usual’ outcome. A sizeable portion of the literature on climate impacts refers to RCP8.5 as business as usual, implying that it is probable in the absence of stringent climate mitigation. The media then often amplifies this message, sometimes without communicating the nuances. This results in further confusion regarding probable emissions outcomes, because many climate researchers are not familiar with the details of these scenarios in the energy-modelling literature. [..] Emission pathways to get to RCP8.5 generally require an unprecedented fivefold increase in coal use by the end of the century, an amount larger than some estimates of recoverable coal reserves. It is thought that global coal use peaked in 2013, and although increases are still possible, many energy forecasts expect it to flatline over the next few decades. Furthermore, the falling cost of clean energy sources is a trend that is unlikely to reverse, even in the absence of new climate policies." Any other suggestions? --Gunnar (talk) 19:12, 24 August 2021 (UTC)

In the graph "Possible Futures" SSP5-8.5 is labelled as highly unlikely, SSP3-7.0 as unlikely and SSP2-4.5 as likely, based on the availability of coal reserves. SSP1-1.9 (and obviously SSP1-2.6, which was not included in the this graph but SSP4-6.0 which itself was not in the final IPCC AR6 WG1 report) is not labeled with likely or unlikely, as it depends of actions triggered by humankind. The management principle of effectuation says: you don't need to predict the future if you can shape it. --Gunnar (talk) 06:20, 31 August 2021 (UTC)

Jean Laherrere wrote in Are there enough fossil fuels to generate the IPCC CO2 baseline scenario?, 2019-08-30 "In the last IPCC report AR5 the ”baseline” RCP8.5 (a lie, in fact RCP12) assumes a cumulative CO2 emission from fossil fuels 4 times what is considered as the most probable and in 2100 an annual FF production 7 times the most probable: it is completely unrealistic. [..] Only RCP4.5 is close to the most probable FF production." (p. 25) --Gunnar (talk) 07:32, 3 September 2021 (UTC)


 * - amended Chidgk1 (talk) 07:26, 3 March 2022 (UTC)

Misleading information
Hello Femkemilene, I've got a question. Reading IPCC Sixth Assessment Report I saw the Table "Shared Socioeconomic Pathways in the IPCC Sixth Assessment Report [26]" (Template:AR6 SSP table), which also gives a likelyhood of the given SSPs. However, as far as I knw, the IPCC doesn't state the likelyhood, and if I understand it correctly, the likelyhood is taken from source [27], a comment by Housefather and Peters. I find it deeply troubling that in this article findings from the IPCC and informed guesses in comments are mixed up, especially since I fear most readers don't understand at all, that the likelyhood isn't taken from the IPCC, but from a mere comment. In my opinion, this should be deleted, as it is missleading. The entry is about AR6, not some comment published two years ago. What do you think? Unfortunately I am not that deep in the AR6 that I could change that myself. Greetings, Andol (talk) 14:24, 2 March 2022 (UTC)


 * I agree that it seems like these likelihoods are attributed to the IPCC and that the IPCC has failed to give probabilities here. The assessment by Hausfather is highly valuable imo, and should be kept, but attributed, and outside of the table. Femke (talk) 17:32, 2 March 2022 (UTC)


 * Regarding misleading information: The IPCC more or less refuses to talk about likelihoods of the IPCC emission scenarios: "the feasibility or likelihood of individual scenarios are not part of the assessment", Box SPM.1.1, WGI AR6. Many readers of the AR reports do not understand the difference between a scenario and a forecast. Therefore it is very much clarifying to give estimates (best guesses) about the likelihood taken from other sources. This will avoid a misdirection of Wikipedia readers, which are in most cases not experts in the lemma's field. Besides the Housefather paper, other publications from the International Energy Agency and the Carbon Action Tracker also suggest that a likely scenario such as Stated Policies/Policies & Action (meaning business as usual according to current state of the art) or Announced Pledges/Pledges & Targets (meaning already committed but not yet implemented policies to GHG reduction) will result in a median temperature rise of 2,6 K and 2,1 K in 2100 according to IEA ([1/3; 2/3] confindence interval 2,4 K – 2,8 K and 1,9 K – 2,3 K) and a median value of 2,7 K and 2,1 K according to CAT. This supports the view that SSP2-4.5 with 2,7 K will be likely, whereas SSP1-2.6 with 1,8 K (range 1,3 K – 2,4 K) needs more efforts than the pledges already in place. SSP1-1.9 with 1,4 K (1,0 K – 1,8 K) needs a stringent intensification of today's climate protection policies and pledges. But SSP3-7.0 and SSP5-8.5 are not likely at all (also because reserve estimations for fossil fuels do suggest they are good for 3400 Gt CO2 (BGR 2020, Table 4, p. 41): they may be useful for intellectual pastimes but are not relevant for practical policy discussions. I'll copy this thread to the relevant discussion page, so it will not get lost in Wikipedia's Vogonian information system. --Gunnar (talk) 11:57, 22 April 2022 (UTC)