Climate change presents the world with a daunting problem. Responding to this problem will require pioneering efforts in science, politics, pollution control, forest land management and law. This document examines the development of international law on climate change and discusses what issues national and subnational legislative bodies may have to consider regarding climate change mitigation and forests.The paper outlines provisions relevant to forests in the United Nations Framework Convention on Climate Change (UNFCC) and the Kyoto Protocol. Examples of national legal responses to climate change are drawn from the USA, the EU and other northern countries, in addition to Costa Rice and Peru in the south. Legal and institutional issues of forest-based mitigation are discussed, including property and transfer issues, and issues of tax and subsidies.The concluding section asks the questions:what should be the role of legislation in supporting use of forests in greenhouse gas mitigation?what expertise might drafters need to succeed in this area?