Eliminating NO2 emissions from Indian farmlands could cut crop damages amounting to $800 million per year: Stanford study

Eliminating nitrogen dioxide (NO2) emissions emanating from coal-fired power plants over large parts of Indian farmlands could cut crop damages amounting to almost a billion dollars annually, a new study by Stanford University in the United States has found.

The study, conducted by researchers from the Stanford Doerr School of Sustainability, added that NO2 was responsible for dragging down annual wheat and rice yields in many parts of India by 10 per cent or more.

This, it noted, was a matter of concern as both grains are critical to India’s food security.

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,” according to a statement by Stanford.

They found coal power plants affected NO2 concentrations above cropland up to 100 kilometres, or roughly 62 miles, away.

“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, according to the study,” the statement noted.

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 reveals 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,” the statement observed.

The researchers found little overlap among the stations associated with the largest crop losses and those associated with the highest mortality.

“This means benefits from possible emission reductions in the future could be more significant and widely distributed than previously understood,” the article by Stanford stated.

According to the authors, the results highlight “the importance of considering crop losses alongside health impacts when regulating coal electricity emissions in India”.