Clearing the Air: Dairies and Climate Change

By Tom Frantz

Around 3% of California’s greenhouse gas emissions come from dairy cows. Most of these emissions are from industrial sized milk factories found in the San Joaquin Valley. The emissions are from the cows themselves in the form of belches and from the handling of their manure. They involve massive amounts of methane emissions, a strong but short lived climate pollutant. Where carbon dioxide has an average lifetime in the atmosphere of hundreds of years, methane may only survive a dozen years, but it has a warming potential around 25 times more than carbon dioxide.

One of the serious issues with the recent Porter Ranch methane leak is that it was a disaster for green house gas emission reductions here in California. Estimates of the total emissions of methane from Porter Ranch are between 50,000 and 90,000 metric tons. That is equivalent to as much as 2.25 million tons of carbon dioxide over a period of about 4 months. California needs to be reducing their emissions by 4 million tons per year currently to reach 2020 targets and will need to reduce even more quickly to reach 2030 and 2050 targets. In 2013, the last year for which there is data, California reduced its emission rate by a measly one million tons.

Dairy cows in California emit close to 12 million tons of carbon dioxide equivalent every year from mostly methane emissions. So, you might say that industrial milk production in California is putting 80% more global warming gases into the air every day than the Porter Ranch leak. Needless to say the dairy industry has been doing this for a long time and will continue for a long time in the absence of regulations. Unfortunately, no one is seriously trying to plug this other leak in order to save the planet.

It turns out that a dairy of around 3,000 milk cows emits 25,000 tons of green house gases annually. That is the amount separating a minor source from a major source according to state regulations. In California, major sources have to report their emissions and fall under Cap and Trade rules where emissions must be cut or offset by a certain amount annually. There are at least a hundred factory dairies this size or larger in the San Joaquin Valley.

California has refused to regulate these factory dairies for greenhouse gas emissions. It is similar to what California did with other air polluting emissions. Dairies are well known to be the single biggest source of air pollution in the San Joaquin Valley. Yet, even though large dairies are characterized as major sources of air pollution, they do not have to reduce or offset their emissions as other major sources are required. There are a few rules they have to follow but they do nothing to dent the massive health costs imposed by this industry on the breathing public.

The California Air Resources Board (CARB) is now so desperate to get some of these methane emissions reduced that they are willing to subsidize dairies that will put a methane digester on their manure lagoons. In fact, CARB has recently approved a project which will capture some of this gas from a group of four different geographically concentrated large dairies and send it down a pipeline where it will be classified as a transportation fuel by a distributor who sells compressed natural gas (CNG) for vehicles.

These dairies will be paid a huge amount for this “special” gas because of “avoided” methane emissions. By mixing a very small amount of this “special” gas with a large amount of regular, fossil fuel based, natural gas the distributor will be able to claim their fuel meets the state’s Low Carbon Fuel Standard where the carbon intensity of transportation fuel must be reduced 10% by 2020.

The bottom line is that the dairy industry will be subsidized lucratively to capture a little bit of their methane which is heating up the planet. It is important to realize that these factory dairies are already about as unsustainable and fossil fuel dependent as possible and a huge negative in terms of the environment both locally and globally. So now they get to make money by putting a small dent in their negative impacts.

The promise of combating climate change in California was that we would get cleaner air and a healthier environment in the process. This dairy debacle is perpetuating everything that is wrong with our fossil fuel dependent system. Instead, there should be direct regulations forcing a reduction in greenhouse gas emissions by this unsustainable method of industrial food production. The public may have to pay more for pizza but will certainly be healthier, in a couple ways, by eating less of it.


Longtime clean air advocate Tom Frantz is a retired math teacher and Kern County almond farmer. A founding member of the Central Valley Air Quality Coalition, he serves on the CVAQ steering committee and as president of the Association of Irritated Residents. CVAQ is a partnership of more than 70 community, medical, public health, environmental and environmental justice organizations representing thousands of residents in the San Joaquin Valley unified in their commitment to improve the health of Californians. For more information, visit

  • The Community Alliance is a monthly newspaper that has been published in Fresno, California, since 1996. The purpose of the newspaper is to help build a progressive movement for social and economic justice.

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