The history of climate change legislation and regulations in California dates as far back as 1988, when Assembly Bill 4420 (Sher) became law, and mandated the California Energy Commission to prepare a greenhouse gas (GHG) emissions inventory. The most sweeping climate change legislation was enacted in 2006 – Assembly Bill 32 (Núñez), also known as the California Global Warming Solutions Act. AB 32 mandated the California Air Resources Board (CARB) to formulate and implement a comprehensive GHG emissions reduction plan (referred to as the AB 32 Scoping Plan), including the development of regulations and a cap-and-trade auction, to reduce GHG emissions to 1990 levels by the year 2020. Since the passage of AB 32, climate change mitigation has been a main consideration in much of the resource-related legislation and regulations in California.