The Hindu: Published on 27th Feb 2025:
Why in News?
A new study led by researchers at Stanford University highlights how coal-fired power plants are reducing rice and wheat yield by up to 10% in India. The research systematically links nitrogen dioxide (NO₂) emissions from power plants to crop damage, showing that these pollutants stress plants, hinder enzymatic functions, and interfere with photosynthesis. Given India’s dependence on coal and growing food demand, this finding is critical for policymakers balancing energy production and agricultural productivity.
Key Issues Raised-
Role of Coal-Fired Power Plants in Pollution
Emissions from coal plants include NO₂, SO₂, CO₂, fly ash, and particulate matter, leading to air pollution, acid rain, and crop stress.
Nitrogen oxides (NOₓ), particularly NO₂, are phytotoxic, meaning they negatively affect plant growth by interfering with photosynthesis and creating ozone, which further harms crops.
This study is one of the first to link power plant emissions directly to crop losses in India.
Use of Satellite Data to Track NO₂ Impact-
Due to lack of ground monitoring in agricultural areas, researchers used satellite images to estimate NO₂ levels.
The study tracked how NO₂ concentrations affected vegetation greenness using the NIRv (near-infrared reflectance of vegetation) index, a known indicator of crop health.
By correlating NO₂ exposure with crop yield reductions, the researchers quantified economic losses from power plant pollution.
State-Wise Impact of Coal Pollution on Crops-
Chhattisgarh had the highest coal-linked NO₂ pollution, affecting monsoon rice (19%) and winter wheat (12.5%).
Uttar Pradesh had high NO₂ levels, but much of it came from non-coal sources.
Tamil Nadu had relatively low NO₂ pollution, but most of it was coal-based, meaning power plants played a key role in pollution.
States with power plants near fertile croplands suffered greater agricultural losses than those with isolated power plants.
Economic Impact of Coal-Related Crop Losses-
Crop damage due to coal-related NO₂ pollution caused monetary losses per gigawatt-hour (GWh) of electricity:
₹15 lakh ($17,370) per GWh for wheat
₹11.7 lakh ($13,420) per GWh for rice
20% of coal-fired electricity generation during the monsoon accounted for half of all NO₂-related rice losses.
12% of winter coal generation accounted for 50% of wheat losses.
Potential Agricultural Gains from Pollution Control-
If coal-fired pollution were controlled, cropland near power plants could experience significant yield recovery:
West Bengal: Up to 5-10% increase in 5.7% of cropland
Madhya Pradesh: 5.9% of cropland could see 5-10% higher yields, while 11.9% could increase by over 10%.
Annual potential gains:
₹3,500 crore ($420 million) in rice production
₹3,300 crore ($400 million) in wheat production
Total increase: ~₹7,000 crore per year
Implications of the Study-
- Coal vs. Agriculture Trade-Off – India relies on coal for economic growth, but its impact on food security cannot be ignored.
- Targeting High-Polluting Power Plants – The study suggests prioritizing pollution control at specific plants to maximize agricultural and environmental benefits.
- Improving Air Quality for Better Crop Yields – Pollution-control policies focused on NO₂ reductions can directly boost food production.
- Balancing Energy and Food Security – India ranks 105th in the Global Hunger Index, highlighting the need for better crop yields and food supply stability.
What Happens Next?
Policy Reforms in Power Sector – Policymakers may tighten regulations on NO₂ emissions from power plants.
Targeted Pollution Control Investments – More investment in emission-reduction technology in regions with high agricultural losses.
Further Research on Other Pollutants – Expanding studies on how coal-fired plants affect crops beyond NO₂ pollution.
Energy Diversification – Encouraging renewable energy sources to reduce reliance on coal-fired power.
Key Takeaways:
- Coal-fired power plants contribute significantly to air pollution and reduce rice & wheat yields by up to 10%.
- NO₂ emissions stress plants, disrupt photosynthesis, and form ozone, worsening crop damage.
- Satellite-based studies provide a precise understanding of pollution’s impact on agriculture.
- Targeting a small number of highly polluting power plants can yield major agricultural benefits.
- Balancing coal energy production and food security will be crucial for India’s economic and environmental future.
