New York City could be sinking

Source: Architectural Digest

From the Financial District’s sky-high centers of economic power to the pricey pads that rise above Billionaires’ Row, the great volume of towering buildings is part of what gives New York City its identity. But according to new research cited by the New York Post, the weight of those same buildings that give the Big Apple its soaring sense of bravado could contribute to the city's sinking.

That’s according to the work of three University of Rhode Island oceanologists and a researcher from the US Geological Survey, who collaborated to publish their findings in the scientific journal Earth’s Future. The scholars first estimated the cumulative weight of New York’s buildings to be 1.68 trillion pounds and then calculated the downward pressure these buildings exert on the mixture of clay, sand, and slit that make up most of the ground beneath the city’s streets.

Based on their model, New York experiences a “subsidence rate” (the technical term for sinking) of about one to two millimeters per year on average, though Lower Manhattan, as well as particular areas of Brooklyn and Queens, show a propensity for greater subsidence risk. As the authors note in their paper, much of lower Manhattan is currently no more than one to two meters above sea level, possibly exacerbating the effects of climate change in turn.

While one to two millimeters per year may not seem that much, the study’s authors warn that this amount is more than enough to cause major coastal cities serious problems in the future. “The combination of tectonic and anthropogenic subsidence, sea level rise, and increasing hurricane intensity imply an accelerating problem along coastal and riverfront areas,” the paper states. “Repeated exposure of building foundations to salt water can corrode reinforcing steel and chemically weaken concrete, causing structural weakening.”

As the study’s authors further point out, this level of annual collapse could potentially exacerbate the impact of extreme weather events like Hurricane Sandy, which saw seawater pour into New York. Combined research suggests that greenhouse gas could play a role in increasing the frequency of hurricanes, as well as the fact that “the threat of sea level rise is 3–4 times higher than the global average along the Atlantic coast of North America,” this subsidence plays a small but meaningful role in a bigger, more dire picture.

The paper concludes with an emphasis on the importance of strategies that could minimize the impact of inundation from seawater. However, the authors implicitly argue that New York’s developers still aren’t taking the risk of rising waters seriously enough. “New York City is ranked third in the world in terms of future exposed assets to coastal flooding,” the paper reads, and “90% of the 67,400 structures in the expanded post–Hurricane Sandy flood risk areas have not been built to floodplain standards.”

With UN reports estimating that the percentage of the world’s population living in urban areas could increase to as much as 68% by 2050, coastal cities should take notice of New York’s slow sinking. Though it would hardly be prudent to topple every skyscraper and start over, perhaps research like this will inspire ingenious solutions that can help New York rise to the challenge of climate change.