Statehouse Versus Greenhouse.

Problem: In the absence of U.S. federal action to address the problem of climate change, a diverse array of nonfederal policy entrepreneurs and climate action planners has produced an impressive body of plans and policies to fight climate change at the regional, state, and local levels. Their actions are highly laudable, but have they actually reduced greenhouse gas (GHG) emissions? Purpose: This article evaluates the work of a group of innovative state-level policy entrepreneurs whose actions were chronicled by Barry Rabe, and a set of 29 state climate action plans systematically analyzed by Stephen Wheeler. It compares states with and without climate policy entrepreneurs and states with and without climate action plans, asks if either plans or entrepreneurs have been successful in reducing CO2 emissions, and identifies the elements within plans that are associated with the greatest reductions. Methods: The analysis uses multiple regression models to explain changes in per capita CO2 emissions attributable to residential, commercial, transportation, and total nonindustrial end users from 1990 to 2007. A package of control variables accounts for political, social, climatic, economic, and urban form factors, while policy variables isolate the effects of climate policy entrepreneurs, climate action planners, and specific policy recommendations within climate action plans. Results and conclusions: State-level climate actions reduce GHG emissions by a measurable but modest amount: about one half metric ton per person per year. This represents 2-3% of the average American's 24-ton annual total GHG emissions. The reduction is small in comparison to the magnitude of the problem, but a substantial tax increase or population shift away from sprawling areas would be necessary to achieve the same reduction. Specific policies I find to be associated with lower emissions include: building efficiency in both residential and commercial sectors, Leadership in Energy and Environmental Design (LEED) policies in the commercial sector, and California's vehicle efficiency standards in the transportation sector. Takeaway for practice: It is encouraging that we can already identify emission reductions related to state climate action. However, the observed reductions remain small com-pared to the scope of the problem. These findings should persuade states without plans to begin the planning process while encouraging states with plans to encourage more entrepreneurship aimed at developing a second generation of policy options for stabilizing our planet's climate with or without federal action. Research support: None. [ABSTRACT FROM AUTHOR]