Issue: Climate Change

Smokestack exhaust spelling CO2


Chart showing fewer cows produce more milk



With concern about climate change growing, nations are scrambling to figure out how to reduce heat-trapping “greenhouse gases,” which contribute to global warming.

The great majority of greenhouse gas emissions worldwide come from fossil fuel combustion. But how can industries reduce fossil-fuel consumption while still meeting the demands of growing populations for energy, food, goods and services, all of which are still largely dependent on fossil fuel?

In the global context, the U.S. dairy industry is a rare and major success story. Due to innovations in efficiency, dairy farmers have greatly increased milk production while reducing greenhouse gas emissions. A major study by the UN’s Food and Agriculture Organization showed that North America, led by the U.S., has the lowest carbon footprint per unit of milk produced in the world.

The number of dairy cows in the U.S. has dropped from 25.6 million in 1944 to about 9.3 million today. Even with fewer cows, milk production actually increased during the same period by 59 percent. As a result, the overall “carbon footprint” of a glass of milk has shrunk by a remarkable 63 percent.

Although the share of emissions from dairies in California remains relatively small (about 4 percent of the state’s greenhouse gas emissions), California lawmakers in 2016 enacted legislation that aims to reduce methane emissions from dairy manure management to 40 percent less than 2013 levels by 2030. Lawmakers also extended the state’s greenhouse gas emissions reduction target to 40 percent below 1990 emission levels by 2030.

California’s dairy community has been and continues to be a leader in developing new “digester” technologies that have the dual benefit of reducing greenhouse gas emissions and creating renewable energy. Dairy digesters capture biogas from enclosed dairy manure containment ponds or tanks. Like natural gas, manure biogas can be combusted in engines to generate power or in furnaces, stoves and boilers to create heat. It also holds promise as a transportation fuel, especially for heavy-duty vehicles, which would also reslt in reduced Nox and particulate matter emissions.

There are already more than 16 dairy digester projects in California, and the dairy community is working with government agency partners, the energy industry and entrepreneurs to bring more cost-effective, environmental friendly dairy digesters to our state. With continued effort and progress, California families can add clean, green, renewable energy to the list of products they produce for our state and nation. See the map of California dairy manure digester development.