I think the most sensible use of SRM is to head off positive feedbacks. With increasing temperature, the planet starts emitting greenhouse gases on its own, fro

I think the most sensible use of SRM is to head off positive feedbacks. With increasing temperature, the planet starts emitting greenhouse gases on its own, from permafrost melt, forest fires, etc. We can see it in the geological record, where orbital variations cause a modest initial warming, then CO2 increases a lot and warms the planet several degrees more. SRM could help prevent that by directly lowering temperature, which means less CO2 released and less ocean acidification. And it buys us time to decarbonize before things all fall apart.