What percent of global greenhouse gas emissions is agriculture responsible for? I have heard low balling estimates as low as 9%. I have never read of such a low estimate for greenhouse gas emissions for agriculture. I have heard of much higher. So I decide to go on a little search, and compile a few of my findings.
EPA: 24%- “Agriculture, Forestry, and Other Land Use (24% of 2010 global greenhouse gas emissions): Greenhouse gas emissions from this sector come mostly from agriculture (cultivation of crops and livestock) and deforestation. This estimate does not include the CO2 that ecosystems remove from the atmosphere by sequestering carbon in biomass, dead organic matter, and soils, which offset approximately 20% of emissions from this sector.”
IPCC: 24% (probably same source as above)- “Agriculture, deforestation, and other land use changes have been the second-largest contributors whose emissions, including other GHGs, have reached 12 GtCO2eq/yr (low confidence), 24% of global GHG emissions in 2010.”
EPA: 9% (United States only)- “In 2014, greenhouse gas emissions from agriculture accounted for approximately 9 percent of total U.S. greenhouse gas emissions. Greenhouse gas emissions from agriculture have increased by approximately 11 percent since 1990. One driver for this increase has been the 54 percent growth in combined CH4 and N2O emissions from livestock manure management systems, reflecting the increased use of emission-intensive liquid systems over this time period. Emissions from agricultural soil management have also increased by about 5 percent since 1990. Emissions from other agricultural sources have either remained flat or changed by a relatively small amount since 1990.”
FAO: 14.5% (livestock only)- “Total emissions from global livestock: 7.1 Gigatonnes of Co2-equiv per year, representing 14.5 percent of all anthropogenic GHG emissions. This figure is in line FAO’s previous assessment, Livestock’s Long Shadow, published in 2006, although it is based on a much more detailed analysis and improved data sets. The two figures cannot be accurately compared, as reference periods and sources differ.”
Nature: up to 1/3 (global food system in its entirety)- “The global food system, from fertilizer manufacture to food storage and packaging, is responsible for up to one-third of all human-caused greenhouse-gas emissions, according to the latest figures from the Consultative Group on International Agricultural Research (CGIAR), a partnership of 15 research centres around the world.”
WRI: 13% (agriculture narrowly defined, excluding transport)- “Farms emitted 6 billion tonnes of GHGs in 2011, or about 13 percent of total global emissions. That makes the agricultural sector the world’s second-largest emitter, after the energy sector (which includes emissions from power generation and transport).”
“Livestock’s Long Shadow” (FAO): 18% (livestock only)- “Overall, livestock activities contribute an estimated 18% to total anthropogenic GHG emissions from five major sectors for GHG reporting: energy, industry, waste, land use, land use change, land use change and forestry (LULUCF) and agriculture.”
So as low as 13%, as high as one-third if you calculate in the cost of the entire food system (which probably makes more sense). The latter figure would possibly put the food system as the highest emitter of all sectors of the global economy.
If you know of something wrong with these figures, I would love to know.