Food and Climate Change: time to eat less meat. IPCC has been giving this message for a long time and its earlier estimates  are now seen to have underplayed the challenge of biomethane from livestock. Its funny how any analysis which says things aren’t quite so bad  (for example  publicity earlier this month suggesting that 1.5 degree warming might still just be achievable) gets headline news along ‘climate change is overplayed’ lines but studies like this one get far less publicity.

“Global methane emissions from agriculture are larger than estimated due to the previous use of out-of-date data on carbon emissions generated by livestock, according to a study published in the open access journal Carbon Balance and Management.

In a project sponsored by the U.S. National Aeronautics and Space Administration’s (NASA) Carbon Monitoring System research initiative, researchers from the Joint Global Change Research Institute (JGCRI) found that global livestock methane (CH4) emissions for 2011 are 11% higher than the estimates based on guidelines provided by the Intergovernmental Panel on Climate Change (IPCC) in 2006. This encompasses an 8.4% increase in CH4 from enteric fermentation (digestion) in dairy cows and other cattle and a 36.7% increase in manure management CH4 compared to IPCC-based estimates. Revised manure management CH4 emissions estimates for 2011 in the US from this study were 71.8% higher than IPPC-based estimates.”
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