two plus two equals five

Is 350 the New 450? por Marlo Lewis:

That’s inconvenient if the only way to sell energy rationing to a reluctant populace is to claim, over and over again, that climate change is “even worse than scientists previously predicted.”

So the new rhetoric emphasizes the alleged damages of global warming — melting Arctic sea ice, drought in Australia, species migration. And we’re told that these impacts are occurring faster than climate models have predicted.

All of which is obviously question-begging, because if the world isn’t warming, how do we know that, say, drought in Southern California is due to CO2 emissions rather than to ocean cycles or some other factor not related to the greenhouse effect? Indeed, if a change in weather or climatic conditions occurs faster than greenhouse climate models project, that is prima facie evidence that the change is not due to greenhouse gas emissions.

Climate sensitivity is thus redefined to mean climate impacts per a given increment of warming rather temperature change per a given increment of CO2. In short, we’re supposed to believe that less warming than the IPCC predicts leads to worse impacts than the IPCC predicts. Hence the need to make 350 ppm the new 450 ppm.