claim: Some global warming 'skeptics' argue that the Earth's climate sensitivity is so low that a doubling of atmospheric CO2 will result in a surface temperature change on the order of 1°C or less, and that therefore global warming is nothing to worry about.
evidence: In his first paper on the matter, he estimated that global temperature would rise by around 5 to 6 °C ( 9.0 to 10.8 °F ) if the quantity of CO 2 was doubled.