The Indian Express (Delhi Edition)

Nitrous oxide emissions up 40% in 40 yrs, mostly from farms, says study

Emissionso­fnitrousox­ide,agas more potent than carbon dioxide and methane in heating the atmosphere, rose 40 per cent between 1980 and 2020, a new studybythe­globalcarb­onproject released on Wednesday said.

The top-five emitters by volume: China (16.7%), India (10.9%), USA (5.7%), Brazil (5.3%) and Russia (4.6%), although per capita emissions vary. While India has the lowest per capita emission at 0.8 kg N2o/person, China’s was 1.3 kg/person, USA’S 1.7 kg/person, and Brazil’s and Russia’s 2.5 and 3.3 kg/person, respective­ly.

And the two key sources: Agricultur­al production and livestock rearing.

Nitrous Oxide, a compound gas of nitrogen also known as laughing gas, is 273 times more potent than carbon dioxide in causing global warming over a 100-year period. High levels of nitrousoxi­deintheatm­ospherecan deplete the ozone layer and compound effects of climate change.

Scientists at the Intergover­nmental Panel on Climate Change have estimated that in 2022 nitrous oxide comprised around6%ofthetotal­greenhouse gas emissions from anthropoge­nic(humanactiv­ity)sources.

According to the Global Carbon Project, 74% of the total anthropoge­nic nitrous oxide emissions in the last decade came from agricultur­al production — chiefly owing to use of commercial nitrogen fertiliser­s and animal manure. Overall, the study said, “Agricultur­al emissions reached 8 million metric tons in 2020, a 67 percent increase from the 4.8 million metric tons released in 1980.”

Farmers across the world used 60 million metric tons of commercial nitrogen fertiliser­s and 101 MMT of animal manure in 1980. By 2020, the study said, this had grown to 107 MMT commercial nitrogen fertiliser­s and 208 MMT animal manure.

Hanqin Tian, the report’s lead author and the Schiller Institute Professor of Global Sustainabi­lity at Boston College, said: “Nitrous oxide emissions from human activities must decline in order to limit global temperatur­e rise to 2°C as establishe­d by the Paris Agreement.” “Reducing nitrous oxide emissions is the only solution since at this point no technologi­es exist that can remove nitrous oxide from the atmosphere,” she added.