Abstract
Many suggest that we should look backward and measure the differences among various parties' past emissions of greenhouse gases to allocate moral responsibility to remedy climate change. Such backward-looking approaches face two key objections: that previous emitters were unaware of the consequences of their actions, and that the emitters who should be held responsible have disappeared. I assess several arguments that try to counter these objections: the argument from strict liability, arguments that the beneficiary of harmful or unjust emissions should pay, and arguments from distributive justice. I argue that none of these successfully justify a backward-looking approach to the temporally remote portion of the climate burden.