Greenhouse Gases

Greenhouse Gas Inventory

Sonoma County is committed to measuring, tracking, and reporting our greenhouse gas (GHG) emissions to communicate progress and focus our actions. While our ambitious GHG reduction goals take into account the critical role both regional and state entities play, our GHG inventory reflects the sectors and emissions sources that can be reduced through the actions of local governments and regional entities.

The Sonoma County Regional Climate Protection Authority (RCPA) established a baseline communitywide GHG inventory for calendar year 2010 and a backcast inventory for 1990 as part of the Climate Action 2020 and Beyond (CA2020) development process. The RCPA completed a 2018 inventory update to help track progress towards achieving the short and long-term emissions reduction goals established in CA2020.

2018 Inventory Update

Sonoma County emissions in 2018 were 3.41 million metric tons CO2e (MT CO2e), slightly below 2015 emissions of 3.44 MT CO2e. Relative to 1990 emissions, 2018 emissions decreased by 13%. Get the full 2018 Update for a comprehensive greenhouse gas inventory update, with a breakdown of jurisdiction specific emissions.

Download the 2018 Update

Our regional approach to reducing GHG emissions recognizes the shared nature of the challenge as well as the fact that Sonoma County communities each have a different capacity to achieve emission reductions. Additionally, statewide policies and programs to reduce GHG emissions related to building energy and transportation play a critical role and represent 50% of the local GHG reductions needed to reach our 2020 target.

This 2018 inventory report is an important milestone in our work to reduce countywide emissions. It is now time to develop a new strategy to accelerate and focus our efforts to meet our 2030 goal to reduce emissions even further in line with the scientific imperative to avoid the catastrophic impacts of unchecked climate change.

2018 GHG Inventory Webinar: Slides (PDF)  |  Video (MP4)

Countywide Greenhouse Gas Emissions by Source

Transportation continues to be the largest source of emissions for the county, with 60% of total countywide emissions in 2018. Between 2015 and 2018, vehicle miles traveled by residents and workers within the county increased by almost 10%. Emissions during this same time increased by only 3% due to improvements in fuel efficiency, such as a shift to hybrid and electric vehicles.

Emissions from energy used in buildings decreased 12% between 2015 and 2018, or 37% between 1990 and 2018. This reduction is largely attributed to Sonoma Clean Power, which was created in 2014 to provide cleaner electricity. 

Livestock and fertilizer emissions are the third largest source of emissions in Sonoma County, with increased emissions in 2018 due to livestock population growth. These working lands can also be part of the solution by using carbon farming techniques to sequester carbon in the soil.

Emissions from waste sent to landfills decreased 7% between 2015 and 2018. The total tons of waste disposed increased significantly in 2018 due to debris from the 2017 wildfires. However, the resulting debris was largely ash with minimal gases left to escape. Countywide emissions from Water and Wastewater decreased by approximately 4% from 2015 to 2018.

Greenhouse Gas Emissions by Source and Jurisdiction (2010-2018)