Cattle are the largest contributors to global enteric CH4 emissions, the report says, pointing to Asia as the originator of much of the emissions (34%).
The report also places blame on large farms for use of high-energy feed and manure disposal methods, though points out that "both intensive (industrial) and non-intensive (traditional) forms of meat production result in the release of greenhouse gases."
The report, which supports climate change, says ecological foundations of agriculture are "being undermined" and industrial agriculture is "contributing to environmental problems."
Report authors point to fertilizers and crop production as contributors to GHG emissions, but say improving livestock feeding efficiency and reduction of food waste may be effective mitigation efforts. Changes in human diets may be a practical tool as well, report authors note, and "a switch to less 'climate-harmful' meat may also be possible."
The report says a target intake of meat shouldn't exceed 70-90 grams per day per person.
"The human health implications of a reduced meat diet need further exploration, but it seems probable that many benefits would accrue from lower consumption rates in many developed and some developing countries. At the same time, reduced meat production would ease both pressures on the remaining natural environment (i.e. less new land clearance for livestock) and on atmospheric emissions of CO2, CH4 and N2O," the report concludes.
View the full alert on the UNEP website.
Beef Producer blogger Jesse Bussard also has an interesting take on a previous UN study: Beef's 'Sustainability' Involves More Than Greenhouse Gasses