California has taken meaningful steps to reduce greenhouse gas (GHG) emissions.  The Renewables Portfolio Standard Program (RPS) (2002, modified in 2006, 2011) required that renewables make up 20% of the state’s electricity mix by 2010 and 33% by 2020.

Efforts were accelerated with the 2006 landmark legislation, the Global Warming Solutions Act (AB 32).  This set as law that 2020 greenhouse gas emissions cannot exceed 1990 levels.  In 2008, the Sustainable Communities and Climate Protection Act (SB 375) required regional GHG emission reduction targets for cars and light trucks, and coordinates land use, transportation, and housing decisions to help achieve the target.  In 2011, Cap-and-Trade set a declining cap on allowed GHG emissions.  Beginning in 2013 the largest carbon emitters will be required to meet the caps or buy credits.  In 2012 the Advanced Clean Cars Program set GHG standards for cars and light trucks for model years 2017-2025.