Just to add that the majority of geoengineering methods currently proposed - particularly those that reduce absorbed solar radiation (such as stratospheric sulfate and marine cloud brightening) come with some significant side-effects.
Many proposed geoeningeering methods don't treat the problem but just mask the symptoms. For starters, CO2 heats the surface and the atmosphere, but solar radiation primarily heats the surface.
This means you cannot use a reduction in incoming sunlight to fully offset CO2 warming - if you get the surface temperature correct, the atmosphere is still warmer and so you get less rain. For many regions, a reduction on rain might be more important - we wouldn't want to end up killing the Amazon rainforest by accident!
Many proposed geoeningeering methods don't treat the problem but just mask the symptoms. For starters, CO2 heats the surface and the atmosphere, but solar radiation primarily heats the surface.
This means you cannot use a reduction in incoming sunlight to fully offset CO2 warming - if you get the surface temperature correct, the atmosphere is still warmer and so you get less rain. For many regions, a reduction on rain might be more important - we wouldn't want to end up killing the Amazon rainforest by accident!
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2008JD01...