Is California Overstating the Climate Benefit of Dairy Manure Methane Digesters?
By Phil McKenna
A California state grant program designed to reduce greenhouse gas emissions results in the direct release of approximately 225,000 to 300,000 metric tons of carbon dioxide into the air each year, according to an Inside Climate News analysis of state data. The pollution, which comes from burning biomethane fuel that was captured from decomposing cow manure, is equal to the annual greenhouse gas emissions of between 50,000 and 65,000 automobiles.
Related Knowledge Center: Methane
As the production of natural gas from shale fields has expanded, so have methane emissions. U.S. methane emissions grew 27 percent from 1990 to 2009, according to the Energy Information Administration. Methane contributes about 10 percent of all U.S. greenhouse gas emissions and is 25 times more potent a greenhouse gas than carbon dioxide.