“Fossil fuel emissions are stabilizing, at least temporarily, because of less coal use in China and increased renewables and energy efficiency around the world,” Stanford University professor Robert Jackson said after reviewing the new figures.
A growing global appetite for meat, particularly in countries whose economies are growing quickly, is helping to drive the growth in agricultural emissions of methane, which is a potent greenhouse gas.
More than half of farming’s direct climate impact in 2014 was caused by methane released by cows and other large livestock and from their manure. (The U.N.’s figures assume methane is 21 times worse for the climate than carbon dioxide, based on its powerful heat-trapping but short-lived properties.)
“Meat consumption is high in countries like the U.S. and is growing rapidly in China and other parts of the developing world,” Jackson said. “Higher meat consumption means greater agricultural emissions.”
Rice farming also releases substantial amounts of methane, while fertilizers release climate-changing chemicals and fuel burning for farm machinery releases carbon dioxide.
Taken together, pollution released by farming was directly responsible for the global warming equivalent of 5.8 billion tons of carbon dioxide, according to the figures, which were published Monday along with a brief statement.
That may seem like chicken feed compared with the 35.9 billion tons of carbon dioxide or equivalent that the energy sector released in 2014 from burning coal, oil, diesel and other fossil fuels, helping to explain why farming receives less attention than energy.
“The opportunities to improve management and decrease emissions are still very important for agriculture, even if it’s not the biggest piece of this pie,” said James Gerber, a scientist at the University of Minnesota who worked with the U.N. to produce a story that described its new findings.
Gerber said helping farmers improve yields through precise applications of fertilizer, changing rice growing practices and reducing food waste could help reduce farming sector pollution.
World temperatures have risen by nearly 2°F since the Industrial Revolution, causing seas to rise, heat waves to intensify and corals to bleach and die.
A U.N. pact finalized in Paris in December that aims to prevent that temperature rise from doubling in the years ahead focuses heavily on the energy sector. Some countries made climate pledges under the treaty that emphasized environmental reforms of agricultural sectors.