r/science Oct 17 '21

Guardian article with IPCC models of rain, fires, heat and changes due to climate change Environment

https://www.theguardian.com/environment/ng-interactive/2021/oct/14/climate-change-happening-now-stats-graphs-maps-cop26
95 Upvotes

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12

u/Final-Defender Oct 17 '21

Give this a read. It’s super in-depth, well formatted for mobile, has a ton of information organized well.

It also scares the hell out of me.

7

u/pyramidguy420 Oct 17 '21

Best case scenario +1,8C… alrighty we fucked mighty

3

u/grundar Oct 18 '21

Best case scenario +1,8C

That's editorializing on the part of the authors.

The lowest-emission scenario evaluated in the IPCC report is SSP1-1.9 (p.16), which results in a maximum warming of 1.6C (p.18) in mid-century, falling to 1.4C by year 2100. The scenario they choose to call "best case" is SSP1-2.6, which results in net zero emissions much later (2077 vs. 2057).

Interestingly, while the authors did not choose the lowest-emission scenario to call "best case", they did choose the highest-emission scenario to call "worst case" (SSP5-8.5).

Similarly, it's editorializing on the part of the authors to label either SSP1-2.6 (their "best case") or SSP5-8.5 (their "worst case") as "unlikely", as the IPCC report does not appear to provide a scientific basis for that judgement. In fact, it appears to specifically not estimate the likelihood of any particular emissions pathway; from p.15:

"Emissions vary between scenarios depending on socio-economic assumptions, levels of climate change mitigation and, for aerosols and non-methane ozone precursors, air pollution controls. Alternative assumptions may result in similar emissions and climate responses, but the socio-economic assumptions and the feasibility or likelihood of individual scenarios is not part of the assessment."

So while the linked article is a useful compilation of the changes that can be expected at different levels of warming, it's worth keeping in mind that it embodies nontrivial components of the authors' opinions. Given that the authors appear to be reporters and visualization specialists rather than climate scientists, it is most likely appropriate to view this article as illustrative rather than authoritative.