The book "Super Freakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance" discussed one method that only costs on

The book "Super Freakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance" discussed one method that only costs on the order of millions of dollars a year -- I believe it was putting sulphur into the atmosphere to cause a cooling effect. It certainly sounded worth considering.