The world’s essential food grains wheat, rice and maize are facing a silent threat from escalating surface ozone pollution. A groundbreaking study by Professor Jayanarayanan Kuttippurath and his team at the Centre for Ocean, River, Atmosphere and Land Sciences (CORAL), IIT Kharagpur, has sounded the alarm on a growing but under-recognised threat to India’s food security: surface ozone pollution.
Published in the journal Environmental Research, the study titled “Surface ozone pollution-driven risks for the yield of major food crops under future climate change scenarios in India” combines historical trends with future projections using data from the Coupled Model Intercomparison Project Phase-6 (CMIP6).
According to the researchers, potential oxidant surface ozone is increasingly damaging crop productivity by infiltrating plant tissues and disrupting essential physiological functions, particularly photosynthesis. Under high-emission scenarios like SSP3-7.0 and SSP5-8.5, wheat yields could decline by up to 20, while rice and maize could see losses of around 7% each after 2050. The Indo-Gangetic Plain and Central India are identified as especially vulnerable, with ozone exposure during crop growth stages potentially exceeding safe limits by up to six times. The threat is compounded by what the study refers to as a “climate penalty” during India’s rabi and post-kharif seasons, which is expected to worsen surface ozone levels.
Stating that the situation is deeply concerning, the study noted that findings have significant implications for our agricultural productivity and our progress toward the United Nations Sustainable Development Goals of zero hunger and no poverty.
Despite the launch of the National Clean Air Programme (NCAP) to tackle urban air pollution, agricultural regions continue to be overlooked. The study stresses the urgent need for crop-specific air quality policies and the promotion of clean energy and low-emission farming techniques.
The research also explores biological mechanisms of ozone damage, noting that about 45% of surface ozone is absorbed through plant stomata, generating harmful reactive oxygen species that degrade critical enzymes such as RuBisCO. This disruption in photosynthesis reduces crop yields significantly.
While several previous studies in India have used short-term data to estimate yield loss from ozone exposure, this study stands out for its comprehensive assessment of future scenarios. It urges policymakers to transition from high-emission development pathways to more sustainable models such as SSP1-2.6, which could help limit crop damage and preserve national and global food security.
As India remains a major exporter of food grains to Asia and Africa, any significant loss in agricultural output could have global repercussions. The researchers call for immediate and coordinated actions to integrate air quality management into agricultural policy frameworks.