Just How Sensitive Is Earth's Climate to Atmospheric Carbon Dioxide?: Scientific American

Just How Sensitive Is Earth's Climate to Atmospheric Carbon Dioxide?: Scientific American: "Carbon dioxide levels climbing toward a doubling of the 280 parts per million (ppm) concentration found in the preindustrial atmosphere pose the question: What impact will this increased greenhouse gas load have on the climate? If relatively small changes in CO2 levels have big effects—meaning that we live in a more sensitive climate system—the planet could warm by as much as 6 degrees Celsius on average with attendant results such as changed weather patterns and sea-level rise. A less sensitive climate system would mean average warming of less than 2 degrees C and, therefore, fewer ramifications from global warming."