SINDHU JHA
A new study conducted by Stanford Doerr School of Sustainability has revealed that nitrogen dioxide (NO2) was responsible for dragging down annual wheat and rice yields in many parts of India by 10 per cent or more.
The researchers estimated rice and wheat crop losses linked to NO2 emissions from coal power stations for the study. They used a statistical model that combines daily records of wind direction and electricity generation at 144 power stations in India and satellite-measured nitrogen dioxide levels over cropland.
“We wanted to understand the impact of India’s coal electricity emissions on its agriculture because there might be real trade-offs between meeting growing electricity demand with coal generation and maintaining food security,” said Kirat Singh, a PhD student in environment and resources in the Doerr School of Sustainability and lead author of the February 3 study.
The researchers found coal power plants affected NO2 concentrations above cropland up to 100 km away. As per the study, eliminating coal emissions from all farmland within this range during key growing seasons (January-February and September-October) could boost the value of rice output across India by approximately $420 million per year and of wheat output by $400 million per year.
Coal emissions vary across Indian states, accounting for as much as 13-19 per cent of Chattisgarh’s NO2 pollution and contributing only about 3-5 per cent of NO2 pollution in Uttar Pradesh. Besides coal-fired power plants, other NO2 sources include vehicle exhaust and industry. The analysis revealed that the value of lost crop output is almost always lower than the mortality damage caused by any given coal power station. But the intensity of crop damage per gigawatt-hour of electricity generated can often be higher. At 58 of the 144 power stations studied, rice damage per gigawatt-hour exceeded mortality damage. Wheat damage per gigawatt-hour exceeded mortality damage at 35 power stations.
