In 2006, a United Nations report entitled “Livestock’s Long Shadow” claimed that the livestock sector is a major player in climate change, “responsible for 18 percent of greenhouse gas emissions ... a higher share than transport.” Appeals for reducing meat consumption to prevent climate change filled the public media, and they continue today (see this recent opinion blog from the New York Times).
At Alltech’s recent Symposium, UC Davis Associate Professor and Air Quality Specialist Dr. Frank Mitloehner explained why this greenhouse gas (GHG) statistic is misleading. His examination of the issue is detailed in a 2009 study entitled “Clearing the Air: Livestock’s Contributions to Climate Change,” which was co-authored by Pitesky and Stackhouse.
At the Symposium, Mitloehner explained that livestock in developed countries actually make a fairly small contribution to greenhouse gas emissions: in the United States, livestock contribute only about 3 percent of anthropogenic emissions, as compared to 26 percent by transportation and 31 percent by electricity. The 18 percent cited in the UN report is an international statistic, influenced by emissions percentages in developing countries. In these countries, livestock make a greater contribution to total GHG production because the countries have smaller transportation and energy sectors.
Percentages of GHG production in developing countries are also influenced by land-use changes related to livestock production, such as deforestation. Many developing countries are converting land to pasture and cropland in an attempt to develop their economies, just as developed countries have already done. According to Mitloehner, GHG emissions due to deforestation and other land-use change patterns inflate the worldwide, livestock-associated GHG production percentage by as much as one-third.
Mitloehner emphasized the importance of reducing GHG production by improving efficiency and productivity of livestock in developing countries, rather than decreasing milk and meat consumption. The more productive the animal (for example, the more milk produced per cow), the lower the GHG emissions are for a particular amount of product. Improving productivity can be achieved by improving fertility, health, and genetics of the animal, as well as by increasing digestibility of feed. According to Mitloehner, the efficient nature of livestock production in the U.S. makes it a useful model for developing countries.
In the coming years, developing countries should focus on improving digestibility and developed countries should focus on waste management. With the need to feed a world population expected to reach 9 billion by 2050, increased productivity and efficiency, not decreased meat and milk consumption, is the key to reduced GHG production.
To view the Alpha Chimp live scribe for Mitloehner’s talk at the Symposium, check out this link.