Another thing is that Hansen's research focuses much more on how changes in the amount of various greenhouse gases in the atmosphere (along with changes in the

Another thing is that Hansen's research focuses much more on how changes in the amount of various greenhouse gases in the atmosphere (along with changes in the size of icecaps, etc) relate to changes in the average surface temperature required so that which the earth will reach a new equilibrium, radiating as much energy as it receives from the sun, and he has emphasized that it is very difficult to forecast how quickly the earth will move toward any new equilibrium.