A new Food & Water Watch analysis has found that 28 California mega-dairies are emitting enough levels of methane to be able to be picked up by satellites and imaging aircraft, despite benefiting from lucrative environmental credits via California’s signature climate program, the Low Carbon Fuel Standard. All analyzed methane releases occurred after the installation of anaerobic digesters.

Findings include: 

• 28 mega-dairies with digesters feeding into the LCFS program released methane into the air at significant rates after their digesters were installed.
  • At least 22 of the 28 digesters with recorded plumes were subsidized with public or California state funding, amounting to $47 million in state grants from 2017 to 2019.
    
• A total of 119 post-installation methane plumes from these dairies were detected between September 2016 and July 2025.
  
• 97 of these methane plumes have recorded emissions rates, with the average being 301 kilograms of methane per hour. All could be categorized as “super-emitters” under Carbon Mapper’s definition.
  • Just a single hour of pluming at these rates releases the carbon dioxide equivalent of driving a passenger car over 2 million miles, or around the equator 84 times.

“As we embarked on doing this analysis, we knew that California was lavishly rewarding factory farms for producing dirty biogas – but we were still shocked to see how even Carbon Mapper’s sporadic monitoring shows how much methane these facilities are spewing into the atmosphere after digesters were installed,” said Amanda Starbuck, Food & Water Watch Research Director. “Unfortunately, this is likely only the tip of the iceberg and these, and other factory farms are also likely releasing significantly more methane than even this analysis shows.”

Further analysis can be found here.