Greenhouse Gas Emission Inventory

This page last reviewed May 5, 2015

Southern California from orbit (NASA photo)

With enactment of the California Global Warming Solutions Act of 2006, (AB 32; Stats. 2006, chapter 488) the Air Resources Board (ARB) was tasked with several new responsibilities to help address the threat of climate change.

In 2006, the California Legislature passed Assembly Bill 1803, (H&SC §39607.4), which made the ARB responsible for developing and maintaining an inventory of greenhouse gas (GHG) emissions. The GHG emission inventory is essential to monitor California's progress toward GHG emissions goals and mitigation. Emission estimates rely on regional, state, and national data sources and facility-specific emissions data reported through the mandatory reporting program.

The initial GHG inventory efforts established the California 1990 Greenhouse Gas Emissions Level and 2020 Emissions Limit and lead to the adoption of a regulation to require the mandatory reporting of GHG emissions.