Hubris is the reason why billionaires do what they do most of the time. Trying to do geoengineering is precisely the kind of a grand scheme these people would try.

I hear Mars is nice this time of year.

Same, also seen proposals for doing stuff like seeding reflective particles in the atmosphere and other wild ideas. I fully expect that at some point it's going to come to that because the disasters are going to lead to desperate measures.