claim: But his results are evidence that the actual climate sensitivity is about 3°C for a doubling of atmospheric CO2.
evidence: Lindzen has stated that due to the non-linear effects of carbon dioxide in the atmosphere, CO2 levels are now around 30% higher than pre-industrial levels but temperatures have responded by about 75% 0.6 °C ( 1.08 °F ) of the expected value for a doubling of CO2.