[explodingman]

I remember an article on this in the New Scientist a long time ago. It opened with telling us that our grandchildren will be able to identify old photos by the blueness of the sky. SO2 in the sky will reduce the intensity of its colour.

More substantially, the distribution of cooling by latitude from SO2 is different from the distribution of warming from CO2. You can put enough SO2 up there to get the same average cooling as the average warming from the CO2 but either the poles will be warmer and the equator cooler, or vice versa (I forget which way it goes). SO2 is not actually “anti-CO2” at all.

So weather patterns will be quite different in a CO2 + SO2 world, and decisions about the “right” amount of SO2 to pump out will be highly contested