Sources of Green House Gases Emission (Natural and Anthropogenic)

Each major greenhouse gas has both natural and human (anthropogenic) sources, and separating the two matters for deciding what mitigation can realistically target. Carbon dioxide's largest anthropogenic sources are coal-based power generation, vehicle and aircraft engine combustion, and agricultural practices like stubble burning, on top of natural release from organic decomposition, volcanic activity and warm oceans and sediments. Methane — roughly 20 times more effective than CO2 at trapping heat molecule-for-molecule — comes from paddy cultivation, cattle rearing, bacterial activity in water bodies, fossil-fuel extraction, oceans, non-wetland soils and forest or wildfires. Nitrous oxide arises naturally from microbial action in ocean, soil and rainforest systems, and from human sources including nylon and nitric-acid manufacturing, agricultural fertiliser use, manure, catalytic-converter-equipped vehicles and burning organic matter. On the plant side, the warming these gases cause lowers tropical agricultural productivity, brings more frequent heat waves that favour weeds, pests and fungal disease, increases insect-vector-borne epidemics, int …