Or doing mirrors over critical Ice flows (whether from new, high altitude, very large, lighter than air constructs, or from orbit), if our starting assumptions about how you go about it didn't begin with matters of "cost," or market carrying capacities, or who was going to pay the cost.
A great deal, in fact, would be possible if we turned things around so that the main concerns were just having the right people to apply to the problem. The right knowledge available not subject to the dictates of profit, and abundant sources of truly green energy; and then of course the right blend of command and control that was automatically focused on the long term balance between the needs of civilization itself, as well as the needs of the of the individual. This, as opposed to everyone only concerned with their own narrow interests, in ever shorter, always distracted, spans of time.
Unfortunately, the current economic operating system is set up to deny my desired option, and of course, encourage the one I just denigrated. I would hope, then, that you could see where we might want to take a very important first step, just to get our ducks in a row, mind you, that would remove this basic, in the way of everything we need to get done, organizational problem. Just sayin.