Soot and other air pollution may be the cause behind China’s devastating 2013 flood, the country’s worst flood in 50 years, new research suggests.
In July of that year, 94 cm of rain pounded a mountainous region of China’s Sichuan province over a five-day period, resulting in floods and landslides that displaced 300,000 and killed 200.
A group of researchers, led by Jiwen Fan from Pacific Northwest National Laboratory in Richland, WA, discovered that if it hadn’t been for the massive levels of smoke, greenhouse gases and aerosols spewed from local factories into the atmosphere, there would have been 60% less rainfall during that storm.
According to a July 12 Quartz article, the researchers simulated the atmosphere over the heavily industrialized Sichuan basin with varying levels of emissions and pollutants to get these results.
“We were amazed at the scale of the effect the pollution had,” Fan said. “Effectively it redistributed the precipitation from the wide area of the basin into the mountains.”
More than 100 million people call the Sichuan basin their home; the region also hosts a number of heavy industries like iron, steel and energy production. But because the basin is surrounded by mountains, aerosols and other air pollutants become trapped in the air above the province, allowing moisture to build up over time.
This isn’t the first time research has linked air pollution with severe flooding. Studies have suggested that pollutants may be making monsoons in South and East Asia hit earlier and harder. Additionally, Fan believes air pollution was likely responsible for the devastating floods that hit Pakistan just two months after the Sichuan flood.
In the U.S., floods are the No. 1 natural disaster, with more than $3 billion in claims going toward flood damage alone. In addition to floods like the 2013 Sichuan flood, China’s primary environmental challenge may be its inability to control air pollution. Every year, China’s terrible air pollution results in some 400,000 premature deaths.
If anything, findings like these only provide more incentive for world leaders to take drastic action against air pollution at this winter’s Climate Change conference in Paris.