It makes no more sense to be certain that the globe is definitely not warming than to be certain that it definitely is. It makes no more sense to be certain that if the globe is warming it is not due to carbon emissions than to be certain that it definitely is. It makes no more sense to be certain that there will not be dire consequences if the globe is warming than to be certain that there will be.

All public policy deals with uncertainty, which means it is well for policymakers and their critics always to show a bit of humility. That is what is in short supply in the “science is certain” crowd. No chance, not even the slightest that they might be wrong. Let temperatures fail to rise and it is a temporary glitch. Or due to mis-measurement of those temperatures. Or to the need to make adjustments in the elaborate models on which the “certain science” has been based. Anyone who disagrees is a “denier”, a word until now reserved for mullahs who deny the existence of the Holocaust.