This report reviews how trade and climate change policies interact and how they can be mutually supportive. The report uniquely examines the intersection between trade and climate change from four different but correlated perspectives: the science of climate change; trade theory; multilateral efforts to tackle climate change; and national climate change policies and their effect on trade. The report underlines that, as a critical first step, governments must urgently seal a scientifically-credible and equitable deal in Copenhagen: one that addresses the need for both significant emission reductions and adaptation for vulnerable economies and communities. Moreover, it highlights that there is considerable scope and flexibility under WTO rules for addressing climate change at the national level, and that mitigation measures should be designed and implemented in a manner that ensures that trade and climate policies are mutually supportive.