The Chinese real estate industry’s problems have expanded from economic to ecological woes, as new research published in the journal Science found nearly half of China’s major cities are sinking.
Reuters reported 45% of China’s urban land was sinking faster than 3 millimeters per year, with 16% descending at more than 10 millimeters per year. The descent is fueled by both declining water tables and the sheer weight of the construction that the land can no longer hold up.
Researchers at South China Normal University noted that more than 900 million people are living in Chinese cities and warned that “even a small portion of subsiding land in China could therefore translate into a substantial threat to urban life.” This is particularly damaging along the Chinese shorelines, where researchers warned roughly one-quarter coastal land could eventually drop below sea levels.
“It really brings home that this is for China a national problem and not a problem in just one or two places,” said Robert Nicholls at the Tyndall Center for Climate Change Research at Great Britain’s University of East Anglia. “And it is a microcosm of what is happening around the rest of the world.”
Nicholls recommended that China follow the lead of their Japanese neighbors, who responded a similar sinking in Tokyo by banning groundwater extraction in the 1970s.
“Subsidence mitigation should be looked at very seriously, but you can’t stop all of it, so you are talking about adaptation and building dykes,” he said.