The current debate about the introduction of a carbon price in Australia marks the nadir of policy evaluation and political commentary in Australia. It is hard to imagine an economic issue where there could be less reliance on established facts and consistent logic. Then again, recent developments in US politics suggest that we may indeed have a lot further to slide down the slippery slope of “truthiness”. Truthiness is the phrase now widely used in the US to describe “concepts or facts that one wishes or believes to be true rather than concepts or facts known to be true”. In the words of Stephen Colbert, “I don’t trust books. They are all fact no heart”. Truthiness is at the heart of the climate policy debate in Australia, and it is embraced by all sides of that debate.