Climate reparations: Why the polluter pays principle is neither unfair nor unreasonable

The polluter pays principle (PPP) has the form of a reparative principle. It holds that since some countries have historically contributed more to global warming than others, these countries have the follow‐up responsibility now to do more to address climate change. Yet in the climate justice debate, PPP is often rejected for two reasons. First, so the objection goes, it wrongly burdens present‐day individuals because the actions of their predecessors. This is the unfairness objection. The second objection is that early polluters were not aware of the harm that they were doing, and so ought not to be held culpable. This is the objection from excusable ignorance. In this commentary, I defend PPP against these two objections. The aim of this short reflection is not to provide a full justification of PPP, or to respond to all objections that have been made against it. My more limited but, I hope, important goal is to show that PPP is neither immediately unfair (in making innocent parties pay) nor immediately unreasonable (in making excusably ignorant parties pay) as is commonly noted, and is therefore worthy of further consideration as a principle of climate justice.