why SRM is necessary

[Phil M]

Hi, I've heard that SRM is necessary because neither emissions reductions nor GHG removal strategies, even if enacted globally with gusto, can possibly impact rising temperatures before we won't have an ecosystem left that can support human life, or most other life for that matter. So it's really about not having enough time left to NOT turn to SRM, which also voids the moral hazard argument as well. But I haven't been able to find any hard research confirming this. Has anyone found such research?

[Claudia Wieners]

Dear Phil,

I wouldn't phrase it as drastically. If 

-- emission reductions are implemented "with gusto"

-- CDR works fairly well

-- climate sensitivity is not on the higher end of current estimates

the 1.5 degrees goal is still within reach (see the most ambitious scenarios of the recent IPCC AR6 WG1, e.g. SRM fig 4). If furthermore

-- tipping points and other nastiness is indeed limited below 1.5 degrees

there is some hope that even without SRM earth remains liveable, though we would still have serious problems with e.g. sea level rise. 

The question is, do we dare to bet on all these conditions? If not, then we should seriously consider SRM but meanwhile keep reducing emissions as much as we can. 

It is a bit frightening that the only scenario in IPCC AR6 WG1 SPM fig 4 that has a chance to stay below 1.5deg (depends on climate sensitivity) assumes we will have massive net negative emissions from ca 2055, while we still don't know whether such negative emissions are feasible at the required scale: https://www.nature.com/articles/s41467-018-05938-3.

Best

Claudia

ps: I've tried to word these thoughts in a simple way here: https://www.uu.nl/en/news/chemotherapy-for-the-climate-the-need-for-risk-risk-balancing-in-assessing-solar-geoengineering 

Op vr 6 mei 2022 om 16:55 schreef Phil M <eeia...@gmail.com>:

Hi, I've heard that SRM is necessary because neither emissions reductions nor GHG removal strategies, even if enacted globally with gusto, can possibly impact rising temperatures before we won't have an ecosystem left that can support human life, or most other life for that matter. So it's really about not having enough time left to NOT turn to SRM, which also voids the moral hazard argument as well. But I haven't been able to find any hard research confirming this. Has anyone found such research?

--
You received this message because you are subscribed to the Google Groups "geoengineering" group.
To unsubscribe from this group and stop receiving emails from it, send an email to geoengineerin...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/be5b2788-05b7-43cd-bf48-42266cbfcfa9n%40googlegroups.com.