"We have the example of the Palaeocene-Eocene Thermal Maximum event 55 million years ago. About the same amount of CO2 was put into the atmosphere as we are putting in and temperatures rocketed by about 5 °C over about 20,000 years. The world became largely desert. The polar regions were tropical and most life on the planet had the time to move north and survive." http://www.newscientist.com/article/mg20126921.500-one-last-...
"We have the example of the Palaeocene-Eocene Thermal Maximum event 55 million years ago. About the same amount of CO2 was put into the atmosphere as we are putting in and temperatures rocketed by about 5 °C over about 20,000 years. The world became largely desert. The polar regions were tropical and most life on the planet had the time to move north and survive." http://www.newscientist.com/article/mg20126921.500-one-last-...
http://en.wikipedia.org/wiki/Palaeocene-Eocene_Thermal_Maxim...