The US state of California has long been a frontrunner in the development of legislation to curb CO2 emissions and climate change. This article explains the Golden State’s regulatory approach and gives it a regional and global context. By Stephen J Orava and Clinton R Long, King & Spalding, USA.

As the eighth largest economy in the world, the US state of California has emerged as an important laboratory for the development of climate change laws and regulations. The foundation for California’s legal and regulatory framework is Assembly Bill 32 (AB 32), the “California Global Warming Solutions Act of 2006”. The implementation of AB 32 requires California to balance the objective of reducing greenhouse gas (GHG) emissions with the statutory requirement to minimise the risk of carbon leakage.