Livestock and climate change: facts and fiction |
Frank Mitloehner
UC Davis

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Livestock and climate change: facts and fiction

As the November 2015 Global Climate Change Conference COP21 concluded in Paris, 196 countries reached agreement on the reduction of fossil fuel use and emissions in the production and consumption of energy, even to the extent of potentially phasing out fossil fuels out entirely.

Both globally and in the U.S., energy production and use, as well as the transportation sectors, are the largest anthropogenic contributors of greenhouse gasses (GHG), which are believed to drive climate change. While there is scientific consensus regarding the relative importance of fossil fuel use, anti animal-agriculture advocates portray the idea that livestock is to blame for a lion's share of the contributions to total GHG emissions.

Divorcing Political Fiction from Scientific Facts

One argument often made is that U.S. livestock GHG emissions from cows, pigs, sheep and chickens are comparable to all transportation sectors from sources such as cars, trucks, planes, trains, etc. The argument suggests the solution of limiting meat consumption, starting with "Meatless Mondays," to show a significant impact on total emissions.

When divorcing political fiction from scientific facts around the quantification of GHG from all sectors of society, one finds a different picture.

Leading scientists throughout the U.S., as well as the U.S. Environmental Protection Agency have quantified the impacts of livestock production in the U.S., which accounts for 4.2 percent of all GHG emissions, very far from the 18-51 percent range that advocates often cite.

Comparing the 4.2 percent GHG contribution from livestock to the 27 percent from the transportation sector, or 31 percent from the energy sector in the U.S. brings all contributions to GHG into perspective. Rightfully so, the attention at COP21 was focused on the combined sectors consuming fossil fuels, as they contribute more than half of all GHG in the U.S.

GHG Breakdown by Animal Species

Breaking down the 4.2 percent EPA figure for livestock by animal species, shows the following contributors: beef cattle, 2.2 percent; dairy cattle, 1.37 percent; swine, 0.47 percent; poultry, 0.08 percent; sheep, 0.03 percent; goats, 0.01 percent and other (horses, etc.) 0.04 percent.

It is sometimes difficult to put these percentages in perspective, however. If all U.S. Americans practiced Meatless Mondays, we would reduce the U.S. national GHG emissions by 0.6 percent.

A beefless Monday per week would cut total emissions by 0.3 percent annually. One certainly cannot neglect emissions from the livestock sector but to compare them to the main emission sources would put us on a wrong path to solutions, namely to significantly reduce our anthropogenic carbon footprint to reduce climate change.

–Reprinted from Egghead, a blog regarding research at the University of California