Policy Documents

UN Scientist Admits Study Overstated Impact of Livestock on Global Warming

James M. Taylor –
March 26, 2010

A 2006 United Nations study claiming livestock production emits more carbon dioxide emissions than transportation overstates the impact of livestock production on global warming, one of the authors has admitted.

Dr. Frank Mitloehner, an associate professor at the University of California at Davis, has acknowledged the UN study calculated livestock carbon dioxide emissions more liberally than it calculated transportation emissions.

Authors of the UN study included in their livestock emissions calculations not only the carbon dioxide directly emitted by livestock, but also the carbon dioxide emitted as a result of land clearance, fertilizer production, and vehicle use associated with livestock production. On the other hand, the UN study did not include similar related emissions in its assessment of transportation.

“I must say honestly that he [Mitloehner] has a point – we factored in everything for meat emissions, and we didn’t do the same thing with transport,” Pierre Gerber, a policy officer with the UN Food and Agriculture Organization, told the BBC News.

Gerber, nevertheless, said the flaw in calculating relative carbon dioxide emissions does not call the rest of the study into question.

The UN study, Livestock’s Long Shadow, asserts livestock production is one of most environmentally damaging activities on the planet. The study claims “the livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global."

"At virtually each step of the livestock production process substances contributing to climate change or air pollution are emitted into the atmosphere, or their sequestration in other reservoirs is hampered,” argues the study.

Environmental activists and anti-meat groups have seized upon these claims to advocate restrictions on livestock production and meat consumption.