He says, "All the suggestions that we're facing some tipping point and suddenly we might see five or six, seven, eight, ten, twelve, thirteen Celsius of warming for a doubling of CO2, the kind of dramatic figures that have been appearing in some scientific papers, we can now prove that all of those very high end forecasts of how much warming we might get are based on an error in mathematics. Correct for the error and we are back down to a maximum of two, perhaps two and a half Celsius of warming for a doubling of CO2."