Having a comparative analysis of existing high-resolution inventories, the study finds that existing estimates for the country’s emissions vary by up to 37% for the pollutants considered — particulate matter (PM2.5 and PM10), nitrogen oxide (NOx), Sulphur dioxide (SO2) and carbon monoxide (CO).
The CEEW study considered emissions from industries, power plants, road transport, domestic sources and agricultural waste burning, which account for approximately 95% of all the criteria pollutant load emitted.
The analysis also highlights significant variations in sectoral estimates. “For instance, the contribution from the residential sector was found to vary from 27% to 50% of the total PM2.5 emissions in the country. The power sector was found to be the leading source — around 44% to 62% — of SO2 emissions. Most of the above-mentioned estimates also point to the power sector as the leading emitter of NOx,” the study states.
It further finds that Uttar Pradesh is the leading emitter of PM2.5 due to the usage of solid fuels in households. It is closely followed by other states including Maharashtra, Madhya Pradesh, Gujarat and Odisha as the highest emitters of PM2.5, albeit with high variations.
Stating that industries and power contribute significantly to multiple pollutants, programme lead at CEEW and lead author of the study, Tanushree Ganguly, said: “Policymakers should focus on reducing emissions from these two sources on a priority basis. To meet the National Clean Air Programme (NCAP) target of 20-30% 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.”
The study recommends that developing a national emissions database would require consistency in the methods and data sources that will be adopted to calculate annual increase or decrease in emissions. “Government departments need to collaborate with each other for updating the emissions estimates periodically. The Central Pollution Control Board should collaborate with National Knowledge Network (NKN) to develop a comprehensive emissions factor database, which will comprise sector- and region-specific emission factors,” it adds.
Karthik Ganesan, fellow and director – research coordination, CEEW, said: “As a start, India should create a comprehensive and consistent energy balance at a country and state-level to account for use of energy use across sectors — formal and informal. This is the main input to the process of creating the emissions database. Efficient and periodic collection of data from rural households, industry, MSMEs and other parts of our informal economy is necessary to better understand their contribution to pollution in a particular region.”
Ganeshan also said that scientific institutes must prioritize the creation of emissions factors that represent local conditions, technologies and maintenance practices.
What study says
– India needs to develop inventory of baseline emissions
– Existing estimates for emissions vary by 37% for pollutants
– Uttar Pradesh leading emitter of PM2.5, followed by Maharashtra, Madhya Pradesh, Gujarat and Odisha
– Power sector leading source of pollution