"Since the start of the industrial revolution, humans have burned enough coal, oil, and natural gas to produce some two hundred and fifty billion metric tons of carbon. The result, as is well known, has been the transformantion of the Earth's atmosphere. The concentration of carbon dioxide in the air today--three hundred parts per million--is higher than it has been in six hundred and fifty thousand years, and probably much longer. At the current rate of emission growth, carbon dioxide concentration will top five hundred parts per million--roughly double pre-industrial levels--by the middle of the century. It is expected that such an increase will produce an eventual global temperature rise of between three and a half to seven degrees Fahrenheit, and this, in turn, will prompt a sting of disasters, including fiercer hurricanes, more deadly droughts, the disappearence of most remaining glaciers, the melting of the Arctic ice cap, and the inundation of many of the worlds major coastal cities." Elizabeth Kolbert from The New Yorker Nov. 20, 2006