This Practice Note provides an overview of carbon offsetting. It was produced in partnership with Justin Macinante of Edinburgh Law School, University of Edinburgh. It looks at the conceptual and legislative context for compliance markets, including the Kyoto Protocol, the clean development mechanism (CDM) and joint implementation (JI), as well as domestic compliance schemes. It also covers development of the voluntary market and offsetting, including standards and rules, issues with the voluntary market and the nature of credits. It also considers current and future developments.