Reducing greenhouse gas emissions not only lowers expected damages from climate change but also reduces the risk of catastrophic impacts. However, estimates of the social cost of carbon, which measures the marginal value of carbon dioxide abatement, often do not capture this risk reduction...

I offer a selective review of discounting and climate policy. Analytic and numerical models show that different assumptions greatly change the degree to which decisions about climate policy depend on the discount rate. I discuss a claim that standard models exaggerate the current generation's...