“…The second strand analyzes the federal level, focusing on interest groups' impact on the policymaking process, and the consequences for climate policy of the separation of powers between the US executive, legislative, and judicial branches (see Bang, 2010;Bryner, 2008;Fisher, 2004;Jacques et al, 2008;Skjaerseth and Skodvin, 2003;Victor, 2004;Wiener, 2004). The third examines climate policy at state and local levels, including developments in individual states and cities, and differences between policy initiatives in different states and regions (see Betsill and Bulkeley, 2004;Mazmanian et al, 2008;Rabe, 2008;Selin and VanDeveer, 2007;Urpelainen, 2009). In addition to these three main strands, a few scholars have recently begun to study how policymaking levels interact.…”