UPSC Prelims 2019 question on Crop Residue Burning Emissions

Analysis

Crop residues/biomass burning are cheap and easiest method to dispose the leftover crop residues (wheat, rice, sugarcane etc.) after harvesting, for land clearing and pest control.

Burning of crop residues is a common approach to eliminate waste after harvesting all over the world. Burning of these residues emit gases like sulphur dioxide (SO2), oxides of nitrogen (NOx), carbon dioxide (CO2), carbon monoxide (CO), black carbon (BC), organic carbon (OC), methane (CH4), volatile organic compounds (VOC), non-methane hydrocarbons (NMHCs), ozone (O3), and aerosols etc which affect the global atmospheric chemistry and climate.

All four — carbon monoxide (1), methane (2), ozone (3), and sulphur dioxide (4) — are released into the atmosphere due to the burning of crop/biomass residue.