California leads the world in the development of dairy digesters: reducing emissions and creating clean energy.

  • California is the first dairy region in the world to set a goal for a 40% reduction of methane emissions from dairy manure. Due mainly to the development of digesters, the state's dairy farms are currently on track to meet that goal by 2030. California currently has 139 digester projects. 33 are already operating.  

  • By using digesters, California farms are not only helping further shrink dairy’s carbon footprint to unprecedented levels, they are also helping the state transition to clean energy.

  • One cow can produce enough transportation fuel to drive a car across the country. Five cows can power a house for a year.​​

  • ​Dairy digesters are providing the largest greenhouse gas reduction of all investments in California’s climate action portfolio.​

  • The digester grant program is among the most cost-effective programs (ranked second of 69 climate programs), providing one ton of GHG reduction (CO2e) for every $9 invested by the state.

  • Through the development of dairy digesters alone, California dairy farms will soon be reducing a total of more than 2.2 million metric tons of greenhouse gases (CO2e) per year. 

  • More than 116 California dairy farms are currently developing projects that will create carbon-negative transportation fuel to replace the use of diesel in heavy-duty trucks. This exciting development not only reduces GHGs, but also significantly reduces emissions of NOx, a smog-forming gas in California's San Joaquin Valley. 

Updated November 2020

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​Learn more about the Dairy Digester Research and Development Program in the latest annual report to the Legislature on California Climate Investments Using Cap-and-Trade Auction Proceeds. You can also download the following resources.

Learn about the state's dairy methane reduction efforts, including  alternative manure management practices.

Explore the print-friendly map.

Learn how California's dairy digesters are helping improve air quality.

Frequently Asked Questions

How does a dairy methane digester work?

“By covering our pond, we capture the biogas that’s produced from the natural breakdown of manure during storage. You can actually see the plastic tarp on the pond rise as it fills up with biogas.”

– Leo Van Warmerdam, Galt, CA

Dairy digesters capture methane to produce renewable energy

What does "carbon negative" mean?

According to the California Air Resources Control Board, renewable natural gas (rng) from dairy biogas is by far the least carbon-intensive transportation fuel currently available in California with a negative carbon intensity score of -255, making it nearly ten times more effective at reducing carbon in the atmosphere than even electric vehicles. To learn more, see Dr. Mitloehner's explanation in the video, How Can We Reduce Livestock Methane?.

How can CA ensure long-term success?

The dairy community is working with government agency partners, technology providers, the energy industry, entrepreneurs, and others to develop cost-effective, environmentally friendly dairy digesters. Dairy families will need continued cooperation from the state to provide infrastructure and robust markets for renewable energy.


California dairy farmers are leaders in planet-smart dairy practices.

Dairy farmers in California have a long history of working collaboratively with state officials and researchers to improve environmental performance, which has placed them in a strong position to lead the world in the development of climate-smart and overall, planet-smart dairy practices. California dairy farmers, state officials, and other key stakeholders will continue discussing pathways for improving economic and environmental sustainability at the second California Dairy Sustainability Summit, taking place March 25-25, 2020 in Sacramento.

Methane digester on California family dairy
Methane digester development in California
California dairy farmer with methane digester
Dairy digesters capture methane to produce renewable energy
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