Abstract
The paper examines two backward-looking principles about how the costs of mitigating and adapting to climate change should be distributed. According to the polluter pays principle, such costs should be borne by those who caused climate change. According to the beneficiary pays principle, they should be borne by those who have benefited from the activities causing climate change, regardless of whether they took part in such activities or not. The paper unpacks both principles, considers their main problems and contends that, when properly combined, they can address such problems.