Agricultural policy and its potential for unintended impacts on air quality and public health in India

Outdoor air pollution is the world's greatest environmental health risk, and the fine particulate matter (PM2.5) component is a leading cause of morbidity and premature death across much of South Asia. In recent years, a series of severe air pollution episodes have engulfed parts of Northern India in the post-monsoon period, leading to state governments trying to further enforce bans on crop residue burning (CRB), which is believed to be a major PM2.5 source. However, at present many Indian farmers have few affordable alternatives for removing crop residue material before the next planting, so CRB remains widespread. Smoke from the massive number of near simultaneous CRB fires is transported hundreds of kilometres along the Indo-Gangetic Plain (IGP), affecting the quality of the air breathed by hundreds of millions, including in the capital Delhi.

This talk will demonstrate how a combination of Earth Observation (EO) data and air quality modelling has been used recently to better quantify the scale and severity of the CRB contribution to northern India's PM2.5 air pollution. It will discuss the factors that drive seasonal air pollution in the region more generally, and will use EO data and model output to directly address the oft-posed question of whether state government agricultural policies, aimed at reducing environmental degradation, may have inadvertently worsened air pollution episodes across Northern India.

An overview of some of the challenges currently limiting our understanding of environmental and health linkages related to air pollution in India will be presented in the final part of the talk. The areas where EO techniques and data may help will be highlighted, and this will be combined with a summary of some of the air pollution mitigation strategies being implemented through the National Clean Air Programme of India that aim to ultimately reduce the health burden coming from agricultural activities.