U.S. dairy farms, including California dairies, have the world's lowest emissions of climate-changing greenhouse gases, according to a report released April 20 by the United Nations.

American dairy farms emit about 45 percent fewer greenhouse gases per unit of milk produced compared to the global average for dairies, according to "Greenhouse Gas Emissions from the Dairy Sector — A Life Cycle Analysis," published by the U.N. Food and Agriculture Organization (FAO).

Note: The report and FAO news release can be found by clicking here .

According to the FAO report:

• Dairies in industrialized nations in North America, Europe and Australia/New Zealand had the lowest carbon footprint, with North America lowest of all, noting that in agricultural systems used in those countries, "methane emissions per kilogram of milk are relatively low ... this is a consequence of high yields and digestibility of feed ..."
• Dairies in Central and South America and parts of Asia produce three to four times the carbon emissions of North American dairies, while dairies in sub-Saharan Africa produce up to 7 times more emissions.
• California dairy farmers have been particularly successful in achieving the production efficiencies cited in the FAO report. "This is further evidence that California dairy families are leading the way on sustainability issues," said William C. Van Dam, chairman of Dairy Cares. "And while the U.S. is leading the world in production efficiency, we should also note that California dairies have been better than the average U.S. production efficiency for a number of years."

The FAO report adds new context to improve the understanding of where dairies fit in globally when it comes to climate change:

• Beef and milk production from the global dairy herd account for 4.1 percent of global greenhouse gas emissions.
• Milk production: 2.7 percent of GHGs.
• Beef from dairy cows and non-milk producing dairy calves: 1.3 percent.

This new information is consistent with estimates previously established in the U.S.:

• U.S. dairies are estimated to produce less than 2 percent of the nation's GHG emissions (Source: University of Arkansas Applied Sustainability Center).
• California dairies (which produce one-fifth of the nation's milk supply) are responsible for 2.3 percent of the state's carbon greenhouse gas emissions (Source: California Air Resources Board).

How Production Efficiency Works
Since 1944, thanks to improvements in breeding, cattle care, housing and nutrition, U.S. dairy farmers have reduced the carbon footprint of milk by 63 percent. In the same period, U.S. milk production increased by 59 percent, even as the total dairy cattle herd shrank from 25.6 million to 9.3 million cows.

Economic Contribution
In addition to providing one-fifth of our nation's milk supply, affordable nutrition and food security for millions of families, California dairy families create 443,000 jobs statewide and $63 billion in economic activity.