Pollution’s impact on China’s crops is worse

China is turning back to low-cost coal to boost its ailing economy. It’s an understandable reaction to the toll caused by Covid lockdowns. But it will come with a steep price for the environment and the health of its citizens.
It’s also likely to worsen food insecurity in China just as the world is trying to fend off a global food crisis that’s emerged as a result of the global pandemic and the war in Ukraine.
These bleak consequences were laid out in a new peer-reviewed study showing how gases associated with the burning of fossil fuels inhibit crop growth worldwide. The impact on China’s crops is greater than on any other region surveyed, and could account for at least a 25% decline in winter crop yields. Adding more fossil-fuel pollution to Chinese air will only
depress crop yields further, pressuring farmers, prices and — ultimately — food consumers.
For more than a century, botanists have been documenting the many ways air pollution has negative effects on plant growth. For example, nitrogen oxides, a common pollutant associated with burning fossil fuels, inhibits photosynthesis. These impacts aren’t simply confined to factory landscaping. Farmers and researchers have noticed the same impacts on crops.
For example, last year, researchers examined the impacts of air pollutants on corn and soybean production in nine US states between 1999 and 2019. The results were bleak: an average loss of about 5% of corn and soybean production attributable to air pollution over two decades. Notably, yields increased with distance from power plants, many of which burned coal.
Yet there was also an important silver lining in those black clouds. Thanks to the Clean Air Act, the US experienced significant air-quality improvements during the study period. Those improvements, in turn, accounted for roughly 20% of the overall soybean and corn yield gains achieved by US farmers during those same fertile decades.
Unfortunately, pollution — and crop yields — are growing worse in many parts of the world. Emerging markets provide some of the bleakest examples.
A recent survey of Indian air quality and crop yields between 1980 and 2010 — a period of intense growth and pollution — found that wheat yields were 36% lower than they should’ve been without the combined effects of climate change and pollutants like ozone and particulates. In some densely populated Indian states, yield losses were as high as 50%.
China has not fared much better. As far back as the 1990s, researchers estimated that haze depressed yields for roughly 70% of the crops grown in China.
In 1999, a set of researchers went so far as to warn that ground-level ozone, the byproduct of nitrogen oxides and other pollutants, “could hinder efforts to meet increasing food demands in the coming decades.”

—Bloomberg