United States: A new report has stated that New York City is sinking in part due to the extraordinary weight of its vertiginous buildings, worsening the flooding threat posed to the metropolis by the rising seas. The weight of the city’s tall buildings is causing it to subside at an average rate of 1-2mm per year, with certain areas sinking even faster. This subsidence is compounding the effects of sea level rise, which is occurring at a rate twice the global average.
As global warming causes glaciers to melt and seawater to expand, the water surrounding New York City has already risen by approximately 9 inches (22cm) since 1950. This combination of sinking land and rising sea levels means that major flooding events from storms could become up to four times more frequent by the end of the century as hurricanes fueled by climate change become stronger.
“A deeply concentrated population of 8.4 million people faces varying degrees of hazard from inundation in New York City,” the researchers wrote in the new study, published in the Earth’s Future journal.
The authors remarked that the risks faced by New York City will be shared by many other coastal cities around the world as the climate crisis deepens. “The combination of tectonic and anthropogenic subsidence, sea level rise, and increasing hurricane intensity imply an accelerating problem along coastal and riverfront areas,” the researchers observed.
“It’s not something to panic about immediately, but there’s this ongoing process that increases the risk of inundation from flooding. The softer the soil, the more compression there is from the buildings. It wasn’t a mistake to build such large buildings in New York, but we’ve just got to keep in mind that every time you build something there, you push down the ground a little bit more,” Mr. Tom Parsons, a geophysicist at the US Geological Survey who led the new research, noted.
According to Mr. Parsons, New York and other coastal cities “have to get planning for this. If you get repeated exposure to seawater, you can corrode steel and destabilise buildings, which you clearly don’t want. Flooding also kills people, which is probably the greatest concern.”