Instead of putting reflectors into orbit it would be cheaper to use hot air balloons, but in general either reflectors or balloons are the best solution to climate change, because they allow to actually control the weather, and the amount of rain different places get. By creating more rains over sahara, we'll not only get more place to live, but the new ecosystem there would consume all the CO2 that was added by us into atmosphere, so we even wouldn't need to reduce the oil usage for now.

A couple of strategically detonated nukes on a tradwind path should cool things down. The same super computers that predict the weather can predict exact placement and yield.

May I point you to doi 10.1002/2017JD027331 that concluded "This analysis demonstrates that while modest, statistically significant differences occur during the first few years, longer‐term impacts are unlikely, regional in scope, and limited in scale. None of the simulations produced a nuclear winter effect."?

I guess that is good and bad news. Hopefully India and Pakistan don't try and refute the findings.

Since you are now my Oracle, how large of a cold spot can we create using a space based sun shade? What would it take to keep arctic methane in the ground?