If AI really was such a game-changer, it would increase the chances of finding extraterrestrial aliens, not decrease it. If AI allows for superhuman feats of intellect and engineering, then even if 99.9% of all strong AI leads to the destruction of the original civilization, you’d only need the 0.1% of civilizations that develop stable benevolent civilization-boosting AI (let’s call them The Culture). Those would spread around, and we would have seen them. So we’re back at Fermi’s paradox.

since at least the 80s

People have been reliant on “ole’ techno-solutions” since the dawn of humanity 2 million years ago on the African savannah, long before capitalism was even a thing. Just sayin’.

This cloud-brightening stuff seems finicky compared to stratospheric aerosol injection. Clouds are hard for climate models to handle as it is, so it would be hard to predict the impact on climate change ahead of time. If you want to do geoengineering, this seems pretty far down on the list of alternatives.