The food system has been highlighted as a major contributor to greenhouse gas emissions, with food supply thought to account for some 19 per cent of the UK’s emissions, for example. Meat and dairy are thought to account for 40 per cent of food related emissions.

A report late last year by a current and a former environmental expert at the World Bank, Robert Goodland and Jeff Anhang, argued that the greenhouse gases produced in the lifecycle and supply chain of livestock could actually account for as much as 51 per cent of total emissions. This is far more than the 18 per cent suggested by the Food and Agriculture Organization, or the 24 per cent estimation of the European Commission’s Joint Research Centre.

The notion has now become deeply rooted in global warming campaigns, with campaigns such as “Meatless Mondays” in the US (a non-profit initiative in association with the Johns Hopkins’ Bloomberg School of Public Health) and “Less Meat = Less Heat” in Europe.

However, such links are not valid, says Frank Mitloehner, PhD, an Associate Professor in the department of animal science at the University of California, Davis. Speaking at the 239th National Meeting of the American Chemical Society, Mitloehner said that the impact of cutting back on consumption of meat and dairy products would be minimal.

Mitloehner identified a passage from a 2006 United Nations report, “Livestock’s Long Shadow”, as the source of the link between meat and dairy on climate change. The section states: “The livestock sector is a major player, responsible for 18 per cent of greenhouse gas emissions measured in CO2e (carbon dioxide equivalents). This is a higher share than transport.”

While Mitloehner does not challenge the production of methane from livestock, he does question how the UN report calculated its emissions. The UC Davis scientist the livestock emissions were calculated from all sources – from the gases produced by growing animal feed to the processing of meat and milk into foods, and all steps in between – the transportation analysis only factored in emissions from fossil fuels burned while driving and not all the other factors associated with transport.

“This lopsided analysis is a classical apples-and-oranges analogy that truly confused the issue,” said Mitloehner.

Smarter farming and not less farming is the answer, he said. “We certainly can reduce our greenhouse-gas production, but not by consuming less meat and milk,” said Mitloehner. “Producing less meat and milk will only mean more hunger in poor countries.”