The challenge of reducing greenhouse gas emissions will differ from place to place, although it is particularly unique in the case of islands. Islands tend to be highly oil and tourism-dependent. Questions as to what type of market-based mechanism, such as cap-and-trade or a carbon tax, and what type of regional partnerships will be appropriate for an island economy are questions that Hawaii policy-makers face. A 10-member Task Force was created as a result of ACT 234 to develop the work plan for reaching the target reduction. This brieﬁng is designed to help the Task Force and others to better understand what climate mitigation policies have been developed elsewhere, the choices made in developing the policy architecture, what types of economic and environmental analyses support these policy decisions, and how examples of other states, regional cooperatives, and international initiatives may be applicable to the case of Hawaii.