For three years, anti-meat advocates, certain climate-change activists, and some small-farm organizations have used a United Nations report to accuse mainstream meat production of being a significant source of greenhouse gases, which contribute to global warming. But research by an air-quality specialist and associate professor at the University of California-Davis, Frank Mitloehner, finally puts the U.N.’s data into context. The result? Livestock production isn’t nearly the climate bugaboo that some activists claim.

The report, "Livestock’s Long Shadow," issued in 2006 by the U.N.’s Food and Agriculture Organization, claims that livestock production is responsible for 18 percent of global greenhouse gas production – more, Mitloehner points out, "than all transportation, including planes, trains, cars, trucks, and ships, combined." As he told "That piqued our interest."

He and his team checked the U.S. Environmental Protection Agency’s data as well as data from California’s Energy Commission. Both agencies report that all of agriculture, not just livestock production, contributes about six percent of greenhouse gases, with about half that total coming from livestock. "Where do the discrepancies come from? The U.N. report is global and is an average," the professor said. "You come to the conclusion that Third World countries have a very different carbon portfolio than developed countries do. For example, in Ethiopia they have many more livestock animals than they have cars, so livestock production contributes a much greater percentage of greenhouse gases there than cars do."

In his study of the U.N.’s data, titled "Clearing the Air: Livestock’s Contribution to Climate Change," co-authored with Maurice Pitesky and Kimberly Stackhouse, who are both also on the UC-Davis faculty, Mitloehner writes that the U.N. report "has been most instrumental in pointing the public attention to the kinds of environmental consequences in which livestock production can potentially result, with special emphasis on climate change. Unfortunately, some of the report’s key conclusions (i.e., livestock produces more GHG [anthropegenic greenhouse gases] than transportation) have been applied regionally and out of their intended context, leading to significant consequences on major public policy affairs. For example, the statement that 18 percent of anthropogenic global GHGs is caused by livestock production and that livestock produces more GHG than transportation (FAO, 2007) is based on inappropriate or inaccurate scaling of predictions, and thus is open to intensive debate throughout the scientific community. Livestock production in most countries of the developed world (e.g., United States and Europe) has a relatively small GHG contribution within the overall carbon portfolios, dwarfed by large transportation, energy, and other industry sectors. In contrast, livestock production in the developing world can be a dominant contributor to a country’s GHG portfolio, due to the developing world’s significantly smaller transportation and energy sectors."

Mitloehner told that those who have used the U.N. report to criticize mainstream meat production have missed a key point in the document: the FAO advocates more, not less, intensive meat production. With a global population of 9.3 billion predicted by 2040, meat production will need to double to keep the world’s demand for animal protein satisfied. The report notes that the chief source of greenhouse gases from livestock production isn’t the animals themselves but deforestation for livestock production. Confined feeding operations, common in the U.S. and other major developed meat-producing nations, actually reduce the need for deforestation and make better use of resources, according to the professor. "We’re growing more forest in the U.S. than we did 10 years ago," he said, adding: "We’re also producing more food today with fewer resources. That means we’re reducing, not increasing, the environmental impact of food and meat production. Meat production has become less land-hungry. This is factual. And it makes sense."

He also pointed out that the U.N. report does not speculate what the GHG impact would be if livestock production were completely eliminated. "While never explicitly stated in any publication, the idea that if livestock were simply eliminated, 18 percent of anthropogenic GHGs would also be eliminated as well, is unrealistic. In fact, many of the resources previously dedicated to domesticated livestock would be utilized by other human activities, many of which produce much greater climate change impacts," he wrote in "Clearing the Air."

Mitloehner told that he’s disappointed, however, that agriculture is not more active in climate-change negotiations. In December of this year, the U.N. hosts a major climate-change conference in Copenhagen; nations and industries from all over the world will be represented. "But two industries have chosen not to participate," he said. "Agriculture and forestry. And both of them need to be part of this discussion. This is an important discussion, a good discussion."