Question: Is it possible to controll the temperature of the Earth.

Keith Brain answered on 17 Jun 2010:

Maybe. The mean temperature of the earth in a balance between the energy arriving from the sun and the amount reflected or emitted for the earth. We can’t do much about the amount hitting the earth, although some people have talked about giant space nitriles located between us and the sun – I don’t think that will work. Instead, we could change the “albedo” or colour of the earth to make it more reflective, but this is difficult and of limited use because our atmosphere is quite a good insulator. It’s a good insulator in part because of carbon dioxide, so can we change carbon dioxide? Yes- I believe so, by cutting emissions and by considering trapping more of it, in, for example, trees.