He attributes the confusion to the UN report, Livestock's Long Shadow, published by the FAO in 2006, which claims that meat production is responsible for 18% of global greenhouse gas emissions, higher than transportation.

 

Dr Mitloehner presented his findings at this week's American Chemical Society conference in California, pointing out an overstatement of the role livestock play in greenhouse gas emissions.

 

Pierre Gerber, a policy officer with FAO, accepted Mitloehner's criticism.

 

''I must say honestly that he has a point - we factored in everything for meat emissions, and we didn't do the same thing with transport,'' he said.

 

American Meat Institute (AMI) believes the attempts to apply these global numbers to the US are misleading because the vast majority of global greenhouse gas emitted by livestock production results from deforestation to grow crops and pasture. Such changes do not take place in the US, as evidenced by the increase in the total acreage of forested land over the last few decades despite the country's surging agricultural production.

 

US Environmental Protection Agency (EPA) reported that only 2.8% of US greenhouse emissions in 2007 came from animal agriculture. This figure has remained nearly constant since the last two decades, amid the almost 50% rise in US meat production over the same time period.

 

AMI President and CEO J. Patrick Boyle said US livestock and meat producers have taken necessary steps to protect the environment, including improvement in feed efficiency, better manure management strategies and more effective use of cropland.