Context: 

A recent study from Stanford University has shown that emissions from coal-fired power plants are hurting rice and wheat crops in India, reducing yields by up to 10% in some areas.

More on the News:

• The research focused on the effects of nitrogen oxides, particularly nitrogen dioxide (NO₂), on crop growth.
• While the negative effects of pollutants like NO₂ on crops were already known, this study is the first to systematically link coal power plant emissions with crop yield losses in India.
• The study analysed India’s 3 major rice-producing states, Uttar Pradesh, West Bengal, and Punjab, and its 3 major wheat-producing states, Madhya Pradesh, Punjab, and Uttar Pradesh.

Methodology Adopted in the Study:

• To assess the impact of NO₂ on crops, the researchers used satellite data to track NO₂ concentrations across India. 
• Given the lack of ground-based monitoring stations in agricultural areas, they used high-resolution data from the TROPOMI satellite to estimate the levels of NO₂ pollution and its effects on plant health. 
• By measuring the near-infrared reflectance of vegetation (NIRv), a proxy for plant health, the researchers could estimate crop yield losses due to NO₂ exposure.

Key Highlights of the Study

Extent of Yield Loss

• The study found that for every 1 mol/m² increase in NO₂, rice yields dropped by 0.0006 metric tons per hectare during the monsoon season, while winter wheat yields decreased by 0.0007 metric tons per hectare.

Regional VariationsNO2 Source :

• Chhattisgarh has the highest share of NO₂ pollution from coal plants (19% in the monsoon season and 12.5% in winter). 
• Uttar Pradesh have high NO2 levels but coal plants contribute only a fraction to this.
• Tamil Nadu, although having relatively low NO₂ pollution, saw the majority of it emanating from coal-fired power stations.

Economic Consequences of Crop Losses:

• According to the study, India’s rice production could gain $420 million a year and wheat $400 million a year, roughly Rs 7,000 crore in total, if the coal plant pollution is controlled.

Concentration of Polluting Plants

• Not all plants contribute equally to NO2 emissions. About 20% of coal-fired electricity generation during the monsoon season accounted for half of all coal NO2-related rice losses, while 12% of total winter season generation was linked to 50% of wheat losses.

Key recommendations of the study:

• The study emphasizes that targeting a small subset of highly polluting coal power stations could lead to significant improvements in crop productivity. 
• The researchers suggest that policymakers should prioritize pollution control measures at power plants that have the greatest impact on agricultural areas.