Accepting the science does not, however, require one to accept the liberal policy prescriptions. Science is only an input to any policy discussion, and nowhere is this truer than in the case of climate change, where the scientific consensus resolves remarkably little. More carbon in the atmosphere leads to warming, but how much warming? Scientists speak in terms of “climate sensitivity” — how sensitive is the climate to some increase in carbon dioxide? Here there is very little agreement. For instance, the models run by the U.N.’s Intergovernmental Panel on Climate Change (IPCC) in its landmark 2007 report produced ranges of predicted future warming whose high estimates were nearly three times their low estimates. The best case showed warming by 2100 of anywhere from 1.1°C to 2.9°C. The worst case showed a range from 2.4°C to 6.4°C. More recent research suggests that climate sensitivity is likely toward the lower end of previously estimated ranges.
A further question is, For a given level of warming, what damage will result? How much will the sea level rise? How much will weather patterns shift? If storms become both stronger and less frequent, what will the net impact be? Again, the projections vary widely.
Only after the full range of scientific predictions is taken into account does the policy discussion even begin. The world in 2100 will have a level of wealth and technology that we can predict no better than the drivers of the first Model Ts could predict the world of today. How capable of adaptation will such a world be, and how much should we spend today to reduce damage then? Finally, for each specific proposal, what are the actual costs and anticipated benefits?
These are the questions on which conservatives should focus. And it is on this playing field, not in a fight over the basis of the science, that they will prevail. Of course, where dangers are exaggerated or distorted in pursuit of a political agenda those excesses must be confronted. But ultimately, the Left’s policy ideas for unilaterally reducing U.S. carbon emissions are not bad ones because there is no potential threat; they are bad ones because they are unresponsive to the potential threat. By accepting the credibility and good faith of the underlying science, conservatives can ask of every policy proponent: Have you run your idea through the climate models, and are any risks averted or materially reduced? The answer to the latter question in every case will be no.
Reagan did not question whether Soviet nuclear weapons were capable of causing explosions. To the contrary, he declared in his second inaugural address that “we seek the total elimination one day of nuclear weapons from the face of the earth.” And then he eviscerated those who wished to leap from that goal to absurd and self-defeating policy responses.