Post #1608074

Assume AMOC stop as inevitable and the drop to 5sv occurs by 2125. It cools the NH slowly and does the other changes slowly. Once AMOC stops, a 2nd rapid cooling + rapid changes occur, eg., rapid Antarctic heating by 6C, even 10C in some places. The higher the CO2 concentration, the s-lower the cooling and other changes. But: the higher the CO2 concentration, the hotter the Southern Hemisphere gets. Now consider Solar Radiation Meddling, SRM. SRM could only be worth a debate if it could be applied to only the Southern Hemisphere, right? As a tool for keeping the Southern half of the planet as close to the now-climate as possible, despite warming from AMOC slowdown and despite warming from GHG. If SRM can't accomplish that but adds more unknowns to the system, it is bad advice. From 2023 https://www.nature.com/articles/s41558-023-01738-w "…SRM could delay but ultimately not prevent WAIS collapse in a high-emissions scenario." "…indicates that WAIS collapse might be prevented by SRM under an RCP 4.5 scenario even for mid-century interventions, however with a substantial risk of failure (35%)" If a stopping AMOC heats Antarctica by as much as a high emission scenario, SRM won't stop the melting? But that was for a globally acting SRM. I can't find information on whether atmospheric mixing allows the confinement to Southern Hemisphere alone. I've seen a paper looking at SRM to cool the Arctic. Can't find it now. From memory, some latitude confinement was possible when SRM is deployed only on very high latitudes. It still affects mid latitudes then but doesn't go further. Might be the same on the Southern latitudes, dunno. Their jetstream is less wavy due to more sea surface, so mixing of SRM particles can be kept in check even better than in the Northern Hemisphere, I guess.