CH4 has a global warming potential of 25, indicating one gram of CH4 is equivalent to 25 grams of CO2 over a 100-year timeframe. CH4 is the second most important GHG in California, accounting for 9% of 2014 GHG emissions in CO2 equivalent units.
Sources of CH4 in California
Agriculture accounts for the majority of emissions, primarily from livestock enteric fermentation and manure management. Industrial sources and landfills are also important sources of CH4. Other sources contribute only a small fraction to CH4 emissions, and include residential, transportation, electricity generation, and commercial sources.