Even if global climate change is an important issue, why is such drastic action needed now?
Researchers are finding evidence that global climate change is happening faster than had been predicted – even as recently as five years ago. Arctic Ocean sea ice, for example, is melting faster than even the most advanced climate change models predict.1 Many believe that the earth may be approaching a tipping point beyond which climate change becomes irreversible. Leading scientists warn that sustained global warming of more than 2ºC above pre-industrial levels could bring us to that point. To prevent the global average temperature from rising above this level, studies have indicated that we must stabilize the concentration of CO2 and other GHGs in the atmosphere at or below 450 parts per million (ppm). This assumption has been the basis for calls to reduce U.S. GHG emissions at least 80 percent below 2000 levels by 2050. In a report published in April 2008, however, James Hansen and other climate scientists, looking at evidence from Earth’s past experience, conclude that keeping the
