Climate change policy developments are expanding in North America. 1 Many of the most innovative of these policy efforts to combat climate change are taking place at regional and local levels. Several U.S. states and Canadian provinces are forging ahead with climate change action beyond requirements mandated by federal governments (Rabe, 2004; Pew Center on Global Climate Change, 2004; NECC, 2005). The most ambitious regional effort is under development in the northeast by the six New England states (Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut) and five Eastern Canadian provinces (Nova Scotia, Newfoundland and Labrador, Prince Edward Island, New Brunswick, and Quebec). Public and civil society actors across these eleven states and provinces argue that addressing climate change at a regional level offers several advantages over individual state and provincial action. This case of regional climate change policy development is part of growing state-provincial environmental policy interaction (Tomblin and Colgan, 2004; VanNijnatten, 2003; chapters in this volume by VanNijnatten, Schwartz, Sanders and Stoett, and Boardman).