A cooperative cap-and-trade initiative undertaken by the Northeastern and Mid-Atlantic states to reduce carbon dioxide emissions. To address the important climate (greenhouse gas reductions) issue, the RGGI participating states developed and are implementing a regional program for reducing emissions through the implementation of a multi-state market-based emissions trading system. Similar initiatives are being planned in the Midwest, through the Midwestern Greenhouse Gas Accord, and in the West, through the Western Climate Initiative. Source: American Council for an Energy-Efficient Economy