This paper identifies cultural and historical dimensions that structure US climate science politics. It explores why a key subset of scientists—the physicist founders and leaders of the influential George C. Marshall Institute—chose to lend their scientific authority to this movement which continues to powerfully shape US climate policy. The paper suggests that these physicists joined the environmental backlash to stem changing tides in science and society, and to defend their preferred understandings of science, modernity, and of themselves as a physicist elite—understandings challenged by on-going transformations encapsulated by the widespread concern about human-induced climate change.