I have worked as a researcher in weather and climate for 40 years. There is a long held view that science will lose its integrity, and scientists will lose their impartial reputation, if scientists stray into the domain of public policy. This doctrine can be quite comfortable for scientists because it limits their personal responsibility to their technical field of expertise. It can also be comfortable for those in the policy arena because science often presents evidence that can be perceived as a threat to vested interests.