The Impact of Climate Change

In 1908, Arrhenius predicted that a doubling of the percentage of CO2 in the air would raise the temperature of the Earth's surface by 4 degree C. This is pretty much the ballpark figure that the latest IPCC report thinks as the most likely number for doubling of carbon dioxide. But he also saw that actually there was going to that the Earth's temperature was going to rise and by a significant degree.