Continuing its role as a leader in air pollution policymaking, California led the nation by passing the first global warming legislation in the U.S.: the Global Warming Solutions Act or Assembly Bill 32 (AB 32). The legislation requires California to decrease greenhouse gas (GHG) emissions to 1990 levels by 2020 (approximately a 27 percent reduction) using an enforceable statewide target to be phased in beginning in 2012. In addition, in 2005 Governor Schwarzenegger issued Executive Order S-3-05, which charges California with the task of reducing GHG emissions to 2000 levels by 2010, reducing emissions to 1990 levels by 2020, and reducing emissions to 80 percent below 1990 levels by 2050. This report represents a body of work conducted to assist the State of California in its efforts to develop a plan to achieve the emission targets set forth by AB 32. This research includes a literature review, expert interviews, and regional stakeholder workshops to identify and explore possible policy processes (e.g., cap and trade, budgets, feebates, etc.), mechanisms (e.g., smart growth and ITS), and strategies that could be employed to meet AB 32's GHG reduction goals.