Global Warming Limits

[Brian Marsden]

A call to action!

This is the text of a recent presentation by James Hansen, NASA's chief climate scientist. He and colleagues have concluded that the safe upper limit for atmospheric carbon dioxide is 350 parts per million or less. The present level is 385 ppm and rising at 2 ppm per year. In other words we must not just reduce the rate at which we are adding CO² to the atmosphere but we must find a way to achieve a net reduction and we must do it promptly, before we pass the point of no return.

This overview includes links to the full papers on which it is based.

http://www.columbia.edu/~jeh1/2008/TwentyYearsLater_20080623.pdf