Nitrous Oxide Emissions Jump 40% with China as Leading Contributor

Recent findings have highlighted a significant surge in planet-warming nitrous oxide (N2O) emissions, marking a 40% increase from 1980 to 2020. China leads as the primary contributor, with India and the United States also identified as major emitters. This data emerges from a comprehensive report by the Global Carbon Project, which underscores the pivotal role of agriculture in this environmental challenge.

The study reveals that a staggering 74% of N2O emissions over the last decade originated from agricultural practices, specifically the use of nitrogen fertilizers and animal manure. Among the top emitters, following China, India, and the US, are Brazil, Russia, Pakistan, Australia, Indonesia, Turkey, and Canada. Nitrous oxide stands as the third most significant greenhouse gas behind carbon dioxide and methane, boasting a potency 273 times greater than CO2 over a century.

The escalation of greenhouse gases has led to an increase in Earth's average surface temperature by 1.15 degrees Celsius from the pre-industrial average (1850-1900). Notably, anthropogenic N2O emissions account for approximately 0.1 degrees of this warming. The concentration of nitrous oxide in the atmosphere reached an alarming 336 parts per billion in 2022, marking a 25% increase from levels recorded between 1850 and 1900 and significantly exceeding predictions by the Intergovernmental Panel on Climate Change.

Agricultural emissions were reported at 8 million metric tonnes in 2020, up 67% from 4.8 million metric tonnes in 1980. This data was published in the journal Earth System Science Data. To align with the Paris Agreement's goal of capping global temperature rise below 2 degrees Celsius, scientists argue that human-induced nitrous oxide emissions must be reduced by at least 20% from 2019 levels by 2050.

"Nitrous oxide emissions from human activities must decline to limit global temperature rise to 2 degrees Celsius," stated Hanqin Tian, Schiller Institute Professor of Global Sustainability at Boston College and lead author of the report. He emphasized that reducing N2O emissions is imperative as there are no existing technologies to remove it from the atmosphere.

The report also sheds light on the dramatic increase in nitrogen fertilizer use by farmers—from 60 million metric tonnes in 1980 to 107 million metric tonnes in 2020. Additionally, animal manure contributed another 101 million metric tonnes in 2020, bringing total usage to an unprecedented 208 million metric tonnes.

Experts caution that the continuous rise of a greenhouse gas with a global warming potential roughly 300 times greater than carbon dioxide poses severe threats to global climate stability. This situation underscores the urgent need for innovative strategies and policies to mitigate nitrous oxide emissions and safeguard our planet's future.