As evidence of anthropogenic climate change mounts there is a growing concern with, and a pressing need for, legal regimes to curtail the problem. This concern culminated in the recent climate change conference in Copenhagen. The US and the EU, as two of the largest contributors to the problem and as entities wielding significant political power, have a pivotal role to play in the creation and development of these regimes. With this in mind, this paper provides a brief survey of the measures taken in the respective jurisdictions to date to combat climate change. Starting with the Kyoto Protocol, the divergent approaches of the two jurisdictions will be noted and the effectiveness of the two regimes discussed, both in terms of emissions reduction and intangible benefits that have arisen. Some ‘best practice’ principles for the design of climate change law will be discerned, suggesting ways in which future climate change law can be more effective.