Climate change represents the most salient risk we face, and we are already getting a glimpse of the costs. At one time, some Americans even hoped that climate change might benefit them. By assigning little weight — far too little weight — to very adverse outcomes, these studies systematically bias the analysis against doing anything. Whereas a below-threshold level of climate change might not affect the risk of frost or drought, a higher level increases disproportionately the risk of these extreme events. It is precisely when the consequences of climate change are large that we are least able to absorb the costs.
