Earlier this month, the food news cycle took a spin for the better for carnivores concerned with the environmental impact of their diet. Fox News and the Washington Times offered the brightest rays of hope, introducing stories with the headlines "Eat Less Meat, Reduce Global Warming—Or Not" and "Meat, dairy diet not tied to global warming." The Daily Mail followed suit, writing, "Veggies are wrong and eating less meat will NOT save the planet." Others just got uppity, writing headlines like, "Go Veggie to prevent warming? Bull."
As it turns out, the enthusiasm was premature: yet another tawdry example of the media either misreading or willfully distorting a study in order to indulge in another irresistible dose of sensationalism.
Some background. In 2006, the UN Food and Agriculture Organization released a pivotal report called "Livestock's Long Shadow." This extensive study presented a wealth of data supporting the claim that global livestock production accounted for 18 percent of total greenhouse gas emissions. To place their findings in perspective, the authors noted that this figure made livestock a greater contributor to global warming than the transportation sector. Needless to say, heads turned and jaws dropped.
Advocates of reduced meat consumption—not to mention vegetarian and vegan interests—were elated, quickly elevating this finding to the level of dogma. For a while, it was not uncommon to hear people saying that a meat-eating Prius driver has a bigger carbon footprint than a vegan Hummer driver.
But Dr. Frank Mitloehner, an animal scientist at UC-Davis, was skeptical—especially when it came to the transportation comparison. With substantial funding from the Beef Checkoff Program, Mitloeher researched and wrote a peer-reviewed article called "Clearing the Air: Livestock's Contribution to Climate Change." In a talk delivered last month to the American Chemical Society, he drew upon this article to challenge the claim that livestock produce more greenhouse gas than transportation.
The authors of the FAO report, he revealed, took their transportation figure from the International Panel on Climate Change (IPCC). The problem with doing this was that the FAO had applied a far more comprehensive life-cycle analysis to animals than the IPCC had done to transportation, resulting in an overstatement of the effect of animal agriculture on global warming. The comparison of livestock and transportation, he argued, was essentially a comparison between apples and oranges.
A life-cycle analysis (LCA) is a stage-by-stage assessment of where energy is consumed (and greenhouse gases produced) in the production of a particular item. While invaluable in terms of improving energy efficiency, LCAs can vary wildly when it comes to comprehensiveness. When applied to livestock, a competent life-cycle analysis should at least examine the energy required to grow the grain to feed the cattle, to slaughter the animals and process the flesh into edible cuts, to refrigerate and transport the meat, and to dispose of the carcass. It should also measure bovine methane output and the carbon sequestration lost because of deforestation. The FAO was diligent in doing all this.