State-level actions to address global climate change, such as laws and litigation recently undertaken by California and by several Northeastern states to limit greenhouse gas (GHG) emissions, reflect creative legal strategies understandably intended to achieve a major environmental objective while the US federal government has not joined the Kyoto Protocol and has not yet adopted national legislation. But even assuming that forestalling global climate change is urgently needed, state-level action is not the best way to do so. Acting locally is not well suited to regulating moveable global conduct yielding a global externality. Legally, state-level action confronts several obstacles, including the dormant commerce clause, dormant treaty clause, interstate compacts clause, and standing to sue. Politically, local action to limit GHG emissions confronts the obstacle that it would incur in-state costs for minimal in-state benefits (raising the positive question why states are acting at all). Normatively, state-level action would make only a minor difference in global emissions, and may even yield perverse results by spurring emissions leakage to other jurisdictions. Given that such state-level action is actually occurring, its best uses include stimulating technological change, learning from experimentation with policy designs, and fostering momentum for broader national and international action. Yet varied policy experiments may conflict with a larger harmonized regime. The best approach to a global externality is a well-designed global regime that engages all major GHG emitters.
Jonathan B. Wiener, Think Globally, Act Globally: The Limits of Local Climate Policies, 155 University of Pennsylvania Law Review 101-119 (2007)