n the political battles over climate change, there are three distinct and relevant questions. First, does mankind have a material affect on the Earth’s climate? Second, if mankind does impact the climate, is that impact harmful? And third, if we assume that mankind is harming the environment, will any given American policy or collection of policies have a meaningful beneficial impact? So far, the conservative movement has mainly pushed back on the “scientific consensus” related to the first question — the extent of human influence over the Earth’s climate. To see a textbook example, watch Ted Cruz’s recent interview with...