Failure of climate investment — will millions choke on smoke?

Over the last two decades, primary field studies have been undertaken in India to establish that exposure to household air pollution (HAP), resulting from the use of solid cooking fuels, are associated with a wide range of acute and chronic health conditions among adults and children. This includes impacts on chronic respiratory diseases including lung cancer, adult blood pressure and cardiovascular disease, birth weight, child pneumonia, and child growth and development.

Burning solid fuels in inefficient open fires or chulhas in poorly ventilated homes can result in dangerous levels of exposure to multiple harmful air pollutants, including fine particulate matter with an aerodynamic diameter of less than 2.5µm (PM 2.5), black carbon, and carbon monoxide, among others. Quantitative HAP measurements performed across multiple states have shown HAP exposures exceeding the WHO’s air quality guidelines (AQGs) by several orders of magnitude.

While Indian cities, in particular NCR, come to focus often for ambient air pollution (AAP) and have remained as the focal point for the NCAP, the insidious health damaging HAP exposures experienced routinely by rural populations, have largely been missing from the air-pollution discourse.

Until recently, the scale and magnitude of HAP’s contribution to AAP has been under-recognised and poorly characterised and the impact of emissions from solid cooking fuels has been largely overlooked. Newly developed emission inventories estimate that primary PM2.5 emissions, summed across non-attainment cities of the NCAP, contribute a small fraction of state-level emissions (for example, 4 per cent in Uttar Pradesh and 17 per cent in Maharashtra). Further, while the traditional focus has been on coal as the largest sectoral contributor, residential biomass cooking-fuel use dominates emissions across the cleanest to the most polluted air-sheds in India.

The estimates of the contribution of solid cooking fuels to ambient PM 2.5 are also getting more consistent with an estimated median national contribution of 30 per cent, with considerable heterogeneity across states. Granular models conducted under the aegis of the Ministry of Environment, Forests and Climate Change (MOEFCC) now estimate that eliminating residential biomass combustion can reduce average national ambient exposure to fine particulate matter below the national ambient air quality standard (NAAQS) across most districts in India.

Finally, transitioning poor populations from biomass cook-fuels to LPG has often been pitched as being inconsistent with the global “de-carbonisation” and “fossil fuel phase out” goals. However, the use of biomass cooking fuels punishes the climate agenda twice, on account of non-renewable biomass harvesting and release of short-lived climate pollutants during combustion. These climate pollutants like particulate black carbon (or soot) are nearly 1000-times stronger atmospheric warmers, on a per mass basis, than carbon dioxide. Globally and in India, complete transitions to gaseous cooking fuels such as LPG have been shown to result in drastic reductions in emissions of climate-damaging pollutants with health co-benefits from reductions in HAP and AAP.

India has an unprecedented opportunity to demonstrate the feasibility of a public-health intervention focused on eliminating household air pollution. The Pradhan Mantri Ujjwala Yojana (PMUY) has already made hefty infrastructure investments for providing LPG access that cover nearly 99 per cent of households in the country. Recently conducted studies have shown that provision of free LPG results in sustained attainment of the WHO interim target guidelines within the household and a virtual elimination of solid fuel use even among the poorest of biomass-using households. Since both household and ambient air-pollution exposure are causally linked to a range of child and adult health outcomes, mitigating emissions from residential biomass combustion would reduce overall exposure much faster than any other source, translating to a bigger health benefit.

Strengthening PMUY with additional financial resources including further subsidies to enable poor communities to completely transition to LPG would yield transformative co-benefits for the NCAP and public health in India. Cost effectiveness of such strategies have also been noted in a recent World Bank report on addressing air pollution in South Asia.

Global climate investments shying away from promoting near-term transitions from biomass cooking fuels to LPG could leave millions across developing countries in the shadow of unjust transitions that leave vulnerable communities bearing the brunt of energy and health inequities.

Balakrishnan is professor and dean (Research) at Sri Ramachandra Institute of Higher Education and Research, Chennai. Dey is professor at Centre for Atmospheric Sciences and Coordinator of CERCA at IIT Delhi. Venkataraman is the Shobha Dixit Chair Professor of Chemical Engineering and Climate Studies at IIT Bombay. Swaminathan is chairperson, M S Swaminathan Research Foundation, Chennai, and principal advisor, MOHFW