California’s dairy operations are responsible for approximately 45 percent of the state’s methane emissions (other livestock operations contribute an additional 10 percent), and 80 percent of the state’s agricultural methane is emitted on dairies.

Approximately equal amounts of methane come from the anaerobic decomposition of liquid manure and from enteric fermentation (gaseous emissions from the cows themselves).

In 2016, Governor Brown signed SB 1383 (Lara) which includes a statewide target for reducing methane from dairy and livestock operations to 40 percent below 2013 levels by 2030.