India needs to develop and maintain a comprehensive inventory of baseline emissions to ascertain whether its policy and technological interventions are able to reduce air pollution, according to an independent study released on Wednesday by the Council on Energy, Environment and Water (CEEW).
The study, a comparative analysis of the existing high-resolution inventories, finds that existing estimates for India’s emissions vary by up to 37 per cent for the pollutants considered — particulate matter (PM2.5 and PM10), nitrogen oxide (NOx), sulphur dioxide (SO2) and carbon monoxide (CO). The study also found significant variations in sectoral estimates.
The CEEW study considered emissions from industries, power plants, road transport, domestic sources, and agricultural waste burning, which account for approximately 95 per cent of all the criteria pollutant load emitted.
It compared pollutants – PM2.5, PM10, NOx, SO2, and CO – from three global emissions databases – Emissions Database for Global Atmospheric Research (EDGAR), Regional Emissions Inventory in Asia (REAS), Evaluating the Climate and Air Quality Impacts of Short-lived Pollutants (ECLIPSE), and two domestic ones – Speciated Multipollutant Generator (SMoG) and The Energy and Resources Institute (TERI), a release from CEEW said.
The CEEW study also found significant variation in sectoral emissions across the five estimates. For instance, the contribution from the residential sector was found to vary from 27 per cent to 50 per cent of the total PM2.5 emissions in the country. The power sector was found to be the leading source – around 44 per cent to 62 per cent – of SO2 emissions.
Most of the above-mentioned estimates also point to the power sector as the leading emitter of NOx, but according to ECLIPSE the transport sector is the leading emitter.
Programme Lead, CEEW, and lead author of the study, Tanushree Ganguly, said, “To meet the NCAP target of 20-30 per cent reduction in particulate concentration by 2024, we need to estimate emission reductions needed across sectors. Estimating these reductions will only be possible when we have an official, representative emission inventory for India. Our study finds that industries and power contribute significantly to multiple pollutants like PM2.5, SO2 and NOx. Policymakers should focus on reducing emissions from these two sources, on a priority basis.”
The study also highlighted that Uttar Pradesh is the leading emitter of PM2.5 due to the usage of solid fuels in households. It is closely followed by Maharashtra, Madhya Pradesh, Gujarat and Odisha as the highest emitters of PM2.5, albeit with high variations.