New findings reveal that nitrogen dioxide pollution from coal-fired power plants is significantly harming grain production essential for India’s food security, causing declines of 10% or more in various regions. The annual financial impact of these crop damages exceeds $800 million.
A recent study from researchers at the Stanford Doerr School of Sustainability indicates that in numerous areas of India, nitrogen dioxide, a harmful pollutant from coal-based power stations, is leading to annual reductions of over 10% in wheat and rice yields.
Wheat and rice are vital to India’s food security, particularly as the country is the world’s second-most populated nation and home to a quarter of the global undernourished population.
“We aimed to assess the influence of emissions from coal power generation in India on agricultural yields, as there may be significant trade-offs between fulfilling rising electricity demands through coal and ensuring food security,” stated Kirat Singh, a PhD student in environmental resources at the Doerr School of Sustainability and the primary author of the February 3 paper published in Proceedings of the National Academy of Sciences.
The Link Between Clean Air and Food Security
Previous research has attempted to quantify the often-overlooked costs associated with coal combustion for energy by estimating the deaths associated with pollution. Agencies and organizations utilize these data, alongside the economic value of a statistical life, to evaluate the advantages and disadvantages of varying economic strategies and environmental regulations.
However, until now, specific estimates of crop damages attributed to coal-fired power stations, which contribute over 70% of India’s electricity, have been scarce, despite extensive research indicating that air pollutants like ozone, sulfur dioxide, and nitrogen dioxide negatively impact crop yields.
“Crop production is crucial for both India’s food security and economic stability,” remarked senior study author David Lobell, the Benjamin M. Page Professor in the Doerr School of Sustainability’s Earth System Science Department. “While we’ve recognized that better air quality could benefit agriculture, this study is the first to concentrate on a specific sector and gauge the potential advantages of curtailing emissions.”
Key Areas and Seasons Affected by Crop Damage
For this investigation, the researchers calculated the losses in rice and wheat crops linked to nitrogen dioxide emissions from coal power plants. They employed a statistical model that integrates daily data on wind patterns and electricity output at 144 power stations in India with satellite-monitored nitrogen dioxide levels across farmlands.
The findings revealed that coal power facilities influenced nitrogen dioxide levels over agricultural land up to 100 kilometers (about 62 miles) away. Removing coal emissions from all farmland within this radius during critical growing periods (January-February and September-October) could elevate the annual value of rice production in India by roughly $420 million and wheat output by $400 million, as indicated by the study.
“This research highlights the significance of addressing environmental matters through a systems perspective,” commented co-author Inês Azevedo, a professor of energy science and engineering at the Doerr School of Sustainability. “Any initiatives geared towards reducing coal emissions in India must account for the agricultural damage caused by air pollution; otherwise, they risk overlooking a vital aspect of the issue.”
In regions with high levels of coal-powered electricity, such as Chhattisgarh, emissions from coal can account for 13-19% of local nitrogen dioxide pollution, depending on the season. In contrast, states like Uttar Pradesh see coal emissions contribute only about 3-5% of nitrogen dioxide pollution. Other primary sources of this gas, which arises from fossil fuel combustion, include vehicle emissions and industrial activities.
Widespread Benefits from Reducing Emissions
The investigation showed that the economic loss from reduced crop yields is nearly always lower than the mortality damage linked to any specific coal power plant. However, the agricultural damage per gigawatt-hour of electricity generated can often surpass the associated mortality damage. At 58 of the 144 examined power stations, rice damage per gigawatt-hour was higher than mortality damage, while at 35 plant locations, wheat damage per gigawatt-hour exceeded mortality damage.
“It’s unusual to find a single intervention, like reducing coal emissions, that could rapidly and significantly benefit agriculture,” asserted Lobell, who also directs the Center on Food Security and the Environment at Stanford.
The research identified minimal overlap between the power stations with the most considerable crop losses and those with the highest mortality rates. This indicates that the benefits from potential future emission reductions may be broader and more substantial than previously recognized. The authors emphasize “the critical importance of considering agricultural losses alongside health impacts when establishing regulations for coal electricity emissions in India.”
“Well-crafted policies aimed at lowering emissions could yield thousands of dollars in increased crop output for every clean gigawatt-hour, in addition to the climate and public health advantages,” said Singh.
Lobell also holds the position of William Wrigley Senior Fellow at the Stanford Woods Institute for the Environment and is a senior fellow at the Freeman Spogli Institute (FSI) and the Stanford Institute for Economic Policy Research (SIEPR).
Azevedo is also an adjunct professor of civil and environmental engineering, a collaborative department between the Doerr School of Sustainability and the Stanford School of Engineering. She is also a senior fellow at both the Stanford Woods Institute for the Environment and the Precourt Institute for Energy.
