Cutting Greenhouse Gases From Food Production Is Urgent, Scientists Say

Rising greenhouse gas emissions from worldwide food production will make it extremely difficult to limit global warming to the targets set in the Paris climate agreement, even if emissions from fossil-fuel burning were halted immediately, scientists reported Thursday.

But they said that meeting one of the targets, limiting overall warming this century to 1.5 degrees Celsius, or about 2.7 degrees Fahrenheit, could be achieved through “rapid and ambitious” changes to the global food system over the next several decades, including adopting plant-rich diets, increasing crop yields and reducing food waste.

“If we’re trying to meet the 1.5-degree Celsius target there is no single silver bullet that is going to get us there,” said Michael Clark, a researcher at the Nuffield Department of Population Health at the University of Oxford in England and the lead author of the new research, an analysis of the climate effects of global food production published in the journal Science. “But together all of them will.”

Meeting the 2-degree Celsius target would be easier, Dr. Clark said. But in both cases, he added, the analysis is based on immediately reaching “net zero” emissions from the burning of fossil fuels for electricity, transportation and industry. Although countries have pledged to reduce them, current fossil-fuel emissions are nowhere near zero, and once they are factored in, he said, “any food transition probably needs to be larger and faster.”

Food production results in emissions of carbon dioxide, methane and other planet-warming gases in many ways, including land clearing and deforestation for agriculture and grazing, digestion by cattle and other livestock, production and use of fertilizers and the cultivation of rice in flooded paddies. Overall emissions are equivalent to about 16 billion metric tons of carbon dioxide a year, or about 30 percent of total global emissions.