Coal energy is costing India as much as 10% of its rice and wheat crops

In line with new analysis led by researchers at Stanford College within the US, coal-fired energy crops are quietly depleting India’s rice and wheat output, destroying as much as 10% of the yield in a number of states.

The emissions from coal energy crops embody carbon dioxide, nitrogen oxides, sulphur oxides, fly ash, soot, suspended particulate matter, and different hint gases. These pollution have been linked to smog, acid rain, eutrophication and varied different environmental burdens.

An elusive hyperlink

Within the new examine, PhD pupil Kirat Singh and his colleagues turned the highlight on the much less explored penalties of nitrogen dioxide (NO₂) on crop productiveness.

The nitrogen oxides generally are a longtime aspect impact of India’s coal dependence. They’re phytotoxic, that means they stress crops, and have been identified to hinder mobile perform and intrude with essential enzymatic actions. The oxides additionally contribute to the formation of ozone, which in flip exacerbates crop injury and produces particulate matter that limits the quantity of daylight out there for photosynthesis.

“We all know that coal-fired energy crops contribute considerably to air air pollution,” Singh mentioned. “And we additionally know from previous research that varied pollution, together with NO₂, can negatively affect crop development. However there hadn’t been a examine linking the 2 in a scientific approach on the power-plant degree, notably in India.”

Monitoring plant well being

To compensate for the shortage of floor monitoring stations in agricultural areas, the researchers used knowledge from satellite tv for pc photographs to glean high-resolution insights into NO₂ focus throughout India. Since a number of energy crops contribute to NO₂ air pollution throughout totally different distances, the researchers summed up all coal-attributable NO₂ emissions reaching every location as a substitute of isolating particular person sources. This strategy gave them a complete image of the quantity of air pollution to which agricultural areas had been uncovered.

Then, to estimate how NO₂ from coal-fired energy crops affected crop yield, the researchers turned to a satellite-derived vegetation index. They used a bodily sign referred to as near-infrared reflectance of vegetation (NIRv) as a proxy for plant well being. NIRv measures greenness. Wholesome crops are richer in chlorophyll, which might’t be detected by seen gentle however is delicate to near-infrared gentle. So the next share of near-infrared gentle is mirrored by leaves in wholesome crops.

Utilizing pre-established coefficients, the researchers may hyperlink NO₂ ranges, measured by the TROPOMI satellite tv for pc, to modifications in NIRv. They used India-specific coefficients of 0.0006 for monsoon rice and 0.0007 for winter wheat. For each 1 mol/m² improve in NO₂, for instance, the corresponding drop in NIRv was 0.0006 and 0.0007, respectively.

Prior analysis has already proven a linear relationship between NIRv and crop yield, permitting the researchers to instantly estimate how a lot yield was misplaced as a consequence of air pollution. They set a baseline NIRv of 0.007, representing zero crop development, and calculated the proportion lower in yield based mostly on pollution-driven declines in greenness. This methodology helped them quantify the agricultural injury wrought by NO₂ with out requiring bodily subject measurements.

Blowin’ within the wind

In addition they analysed wind patterns to distinguish between air pollution from coal crops from that from different industrial and environmental sources. This step helped the staff unravel main variations within the results of coal air pollution throughout States.

For instance, Chhattisgarh, a serious hub for coal-fired energy, had the best share of NO₂ air pollution from coal crops: about 19% of NO₂ detected within the monsoon season and 12.5% in winter got here from coal crops.

Surprisingly, Uttar Pradesh had excessive total NO₂ ranges however solely a small portion of that got here from coal energy, whereas Tamil Nadu had comparatively low NO₂ air pollution however the bulk of it got here from coal energy.

Coal’s contribution to air air pollution thus diverse by area. Not all energy crops have the identical affect: these positioned close to fertile farmland with a excessive emissions publicity brought on essentially the most agricultural injury, Singh mentioned.

An neglected loss

Crop injury depth — measured as monetised loss per gigawatt-hour (GWh) of electrical energy generated — for wheat and rice touched as much as $17,370/GWh (Rs 15 lakh on February 6, 2025) and $13,420/GWh (Rs 11.7 lakh) respectively.

About 20% of coal-fired electrical energy era in the course of the monsoon season accounted for half of all coal NO₂-related rice losses whereas 12% of complete winter season era was linked to 50% of wheat losses.

This advised that concentrating on a comparatively small subset of extremely polluting energy stations may nonetheless have important advantages for agricultural productiveness. To wit, as per the examine, the yield of 5.7% of cropland in West Bengal close to coal-fired energy stations may improve 5-10% whereas the positive aspects of 1.66% may exceed 10%. Equally in Madhya Pradesh, the yield in 5.9% of cropland may improve 5-10% yield positive aspects and one other 11.9% may achieve by greater than 10%.

To match, the annual yield development for kharif rice and rabi wheat has averaged simply 1.7% and 1.5% respectively between 2011 to 2020.

In line with the examine, India’s rice manufacturing may achieve $420 million a 12 months and wheat $400 million a 12 months, roughly Rs 7,000 crore in complete.

Anticipated yield positive aspects from eliminating coal-attributable nitrogen dioxide concentrations in main rice- and wheat-producing states. Giant tracts of cropland in all key states are anticipated to see yield enhancements of 1% from eliminating coal-related NO2. Information from 2019 rising seasons.
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PNAS: 122 (6) e2421679122

India and coal

Because the 2025-2026 Financial Survey in addition to power specialists have famous, coal energy performs a vital position in India’s development in the mean time. The 2025-2026 Union Price range has allotted 255% extra for the Ministry of Coal over revised estimates of FY 2024-2025.

India’s demand for meals is hovering as effectively. In 2024, the World Starvation Index ranked India one hundred and fifth out of 127 international locations on meals safety. Rice and wheat are staple crops in India and in lots of components of the world to which these grains are exported.

Singh mentioned he hopes to tell coverage reforms that may enable the coal and agricultural sectors to fulfill within the center. “Whenever you’re crafting coverage round controlling air pollution from the ability sector, contemplating crop impacts alongside well being and greenhouse gasoline emissions may also help policymakers prioritise the place that air pollution management tools must be put in,” he mentioned.

“If you wish to optimise the cash that’s being invested in putting in all of this pollution-control tools, you wish to give attention to energy crops the place it might convey essentially the most profit. Policymakers may discover data in our analysis that might be useful by way of determining which energy stations to prioritise,” he added.

Singh grew up in New Delhi and mentioned its poor air high quality motivated him to review the results of air air pollution on human in addition to crop well being. In future, Singh is planning to additional examine how coal energy crops have an effect on agriculture at giant in India, together with the consequences of different pollution on crop productiveness.

Ashmita Gupta is a science author.