Historical accounts of climate change science and policy have reflected rather infrequently upon the debates, discussions, and policy advice proffered by economists in the 1980s. While there are many forms of economic analysis, this article focuses upon cost-benefit analysis, especially as adopted in the work of William Nordhaus. The article addresses the way in which climate change economics subtly altered debates about climate policy from the late 1970s through the 1990s. These debates are often technical and complex, but the argument in this article is that the development of a philosophy of climate change as an issue for cost-benefit analysis has had consequences for how climate policy is made today.