world’s second largest source of nitrous oxide (N2O), a greenhouse gas that heats up the atmosphere far more than carbon dioxide. Nearly 11% of such global man-made emissions in 2020 were from India, topped only by China at 16%. WHAT IS THE MAJOR SOURCE OF NITROUS OXIDE? The major source of these emissions comes from fertilizer usage, according to a global assessment of N2O emissions published in the journal Earth System Science Data. Agricultural production using nitrogen fertilizers, such as ammonia, and animal manure contributed 74% of the total anthropogenic N2O emissions in the last decade.