ABSTRACT
Climate change raises a number of questions of intergenerational equity. One – and the one that attracts the most attention – is the question of what obligations people have to future generations not to engage in activities that will trigger dangerous climate change and thereby impose harms on people in the near and distant future. The question of what we owe to future people is of critical importance when determining mitigation policy for it bears on when any generation should mitigate and by how much. The economic literature on this issue has tended to approach these questions by drawing on the idea of a ‘social discount rate’. The aim in this chapter is to examine the normative force of the considerations that are employed to determine the social discount rate. To do so, I will distinguish between three kinds of consideration invoked in analyses of discounting, assessing in each case their plausibility and their implications for climate change policy. The three kinds are, respectively, Pure Time Discounting, Growth Discounting and Opportunity Cost Discounting. I shall defend the following three claims:
A Pure Time Discounting gives us no reason to delay taking action to mitigate climate change (or for adopting a more gradual approach when implementing mitigation policies).
