New research has quantified the damage caused by pollution from coal power stations on wheat and rice crops in India, finding that these essential crops are yielding up to 10% less when impacted by power stations as far away as 100km.
These crops are critical for India’s food security and while it is recognised that yields are affected by air pollution levels, the impact of coal-fired electricity generation – which provides the country with over 70% of its electricity – has not been quantified.
The researchers specifically focussed on the impact of nitrogen dioxide (NO2) emissions, using a statistical model that integrated daily wind direction data, electricity generation records from 144 power stations in India, and satellite measurements of NO2 levels over agricultural land.
Senior study author David Lobell said: ‘Crop productivity is incredibly important to India’s food security and economic prospect. We’ve known that improved air quality could help agriculture, but this study is the first to drill down to a specific sector and measure the potential benefits of reducing emissions.’
Kirat Singh, a PhD student in environment and resources in the Doerr School of Sustainability and lead author of the study added: ‘We wanted to understand the impact of India’s coal electricity emissions on its agriculture because there might be real trade-offs between meeting growing electricity demand with coal generation and maintaining food security.’
The team found that emissions from these power stations had a bearing on the NO2 concentrations over crops up to 100km away. In some areas, which are heavily exposed to coal-linked NO2, it was found that annual yield can be reduced by over 10%.
They also point out that the total damage to the crops caused by the power stations is likely to be higher, as this research did not include other air pollutants, water stress or heavy metal contamination.
The researchers concluded that were there no such emissions in these areas during the growing seasons – January/February and September/October – the value of the country’s rice and wheat production would increase by around $820 million a year.
David Lobell said: ‘It’s rare to find a single thing – in this case, reducing coal emissions – that would help agriculture so quickly and so much.’
Co-author Inês Azevedo added: ‘This study underscores the importance of looking at environmental issues under a systems lens. Any policy focused on reducing emissions from coal power plants in India will be ignoring a crucial part of the problem if it does not consider the damages from air pollution to agriculture.’
‘Well-targeted policies to cut emissions could deliver thousands of dollars of increased crop output for each clean gigawatt-hour, in addition to all the climate and human health benefits.’
The full research can be read here.
Photo by Dibakar Roy