Food securityGlobal Food Production Poses an Increasing Threat to the Climate

Rising anthropogenic nitrous oxide emissions are jeopardizing climate goals and the Paris Accord, a study published in Nature and led by an Auburn University researcher has found.

The significant use of nitrogen fertilizers in the production of food worldwide is increasing concentrations of nitrous oxide in the atmosphere—a greenhouse gas 300 times more potent than carbon dioxide—which remains in the atmosphere longer than a human lifetime.

This finding is part of a study co-led by Professor Hanqin Tian, director of the International Center for Climate and Global Change Research at Auburn University’s School of Forestry and Wildlife Sciences and an Andrew Carnegie Fellow. The study was published today in Nature, the world’s most highly cited interdisciplinary science journal.

Tian co-led an international consortium of scientists from 48 research institutions in 14 countries under the umbrella of the Global Carbon Project and the International Nitrogen Initiative. The objective of the study, titled “A comprehensive quantification of global nitrous oxide sources and sinks,” was to produce the most comprehensive assessment to date of all sources and sinks of the potent greenhouse gas nitrous oxide.

Tian’s Auburn colleagues including Professor Shufen Pan, postdoctoral fellows Rongting Xu, Hao Shi and Yuanzhi Yao and graduate student Naiqing Pan served as co-authors among an international research team of 57 scientists.

The study points to an alarming trend affecting climate change: Nitrous oxide has risen 20 percent from pre-industrial levels, and its growth has accelerated over recent decades due to emissions from various human activities.

“The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions,” Tian said. “There is a conflict between the way we are feeding people and stabilizing the climate.”

The researchers further identify an emerging cause of increased atmospheric nitrous oxide coming from the interaction between global warming and nitrogen additions for food production further enhancing emissions from agriculture. Warmer temperatures tend to increase nitrous oxide emissions.

The study also determined that the largest contributors to global nitrous oxide emissions come from East Asia, South Asia, Africa and South America.

Emissions from synthetic fertilizers dominate releases in China, India and the U.S., while emissions from the application of livestock manure as fertilizer dominates releases in Africa and South America, the study found. The highest growth rates in emissions are found in emerging economies, particularly Brazil, China and India, where crop production and livestock numbers