Major Sources Contributing to Current and Future Fine Particulate Pollution in India

Air pollution in India is a major public health issue. In 2013 ambient air pollution caused 587,000 deaths, while household air pollution caused 924,000 deaths. While household air pollution is from biomass fuel burning, ambient air pollution arises from many sources..  Ambient air pollution results from sources which either directly emit fine particles or emit gases that convert to particulate matter in the atmosphere. Estimation of source-specific emissions is the first step in estimating the health impacts of air pollution from major sources.

We estimate current and future emissions of PM-2.5, mass of particles smaller than 2.5 microns in size, and its precursors from industry, transport, residential and agriculture, accounting for emissions from different technology types.  Current emissions in India arise from three main sources. These are (i) biomass-fuelled, high-emitting, traditional technologies in individual homes, brick production and informal industry, (ii) coal burning in power generation and heavy industry and (iii) open burning of agricultural residues for field clearing.

Under climate policies to curb GHG emissions, India plans a major share of non-coal based electricity generation (40% by 2030), along with energy efficiency increases in heavy industry. Proposed environmental legislation includes an auto-fuel policy in the transport sector and new emission standards for power plants and brick kilns. Future emissions are estimated assuming three scenarios with increasing levels of energy efficiency and emission controls.

In scenarios of current and moderately aspirational policies, expansion in electricity generation and industry overtakes emission offsets, leading to 1.5-2 and 1.75-3 times emission increases, respectively, in PM-2.5 and its precursor gases, through to 2050. In the third scenario, adoption of ambitious polices, currently not formulated, leading to major diffusion of clean technologies and practices, delivers significant reductions in 2050, to levels of 0.5 and 1.1 times, respectively, of present day emissions of PM-2.5 and its precursor gases. Future source contributions to PM-2.5 and precursor gas emissions are about 60% from coal burning in electricity generation and industry, with the remainder from biomass energy use in the residential sector.

Mitigation of air pollutant emissions in India requires a three-pronged approach enabling a switch away from biomass-fuelled traditional technologies, industrial coal-burning and open burning of agricultural residues.