“I don’t think that mass murderers of the usual kind, such as Breivek, should face the death penalty. Nor do I think tobacco denialists are guilty enough to warrant the death penalty, in spite of the enormous number of deaths that resulted more or less directly from tobacco denialism.

GW is different. With high probability it will cause hundreds of millions of deaths. For this reason I propose that the death penalty is appropriate for influential GW deniers. More generally, I propose that we limit the death penalty to people whose actions will with a high probability cause millions of future deaths.”

Richard Parncutt, a Professor at the University of Graz, Austria. “Death Penalty for Global Warming Deniers?” 25 Oct 2012