New York’s a Lot Like Venice. It’s Sinking. By James Barron, May 23, 2023, New York Times
Maybe you have had that sinking feeling lately. A recently published scientific paper suggested that all of New York has and will continue to. The paper said that New York sinks between two and four millimeters a year under the weight of all the buildings, “with some areas subsiding much faster.” A couple of millimeters is so little that the finding almost sounds amusing. Four mm is 3-20ths of an inch. But the finding about the city’s slow and gradual descent was not intended to be funny. “And that’s the point,” said Tom Parsons, a geophysicist with the United States Geological Survey who was the lead author of the paper.
The concern is that the downward force of the buildings, coupled with rising water levels from global warming, could make the city more prone to natural disasters. Those factors “imply an accelerating problem along coastal and riverfront areas,” he wrote in the paper, published in the journal Earth’s Future. “The point of the paper is to raise awareness that every additional high-rise building” along a river “could contribute to future flood risk.”
What is happening in New York is “quite comparable to what’s happening in Venice,” he said in an interview. “They’re sinking at the same rate.” But in Venice, climate change is outrunning the projections that a $5.3 billion system of sea walls was designed to withstand.
And Indonesia is building to build a new capital city from scratch because the current one, Jakarta, is sinking. The president, Joko Widodo, gave up on trying to save Jakarta after raising sea walls and trying other measures. My colleague Hannah Beech called them “duct-tape solutions” that could not put Jakarta beyond the reach of the water.
Parsons is not calling for a new New York on higher and dryer ground. “It’s not an emergency now,” he said. “What we wanted to do is provide this science that’s help for planning down the road. It’s easy for scientists to show up as an emergency is happening, but it’s more useful to start talking about this early enough that something can be done to mitigate it.”
“That’s the main question I get, how do we mitigate this,” he added. “The answer a lot of people don’t want to hear is the greenhouse gas side of it. We can slow sea-level rise if collectively we can find a way to reduce the amount of greenhouse gases in the atmosphere. That’s not an easy task, obviously.”He cited a United Nations projection that 70% of the world’s population will inhabit cities by 2050. “When you build a city and it gets full of people, you end up with subsidence,” he said, saying that New York City was “emblematic of a place that people migrate to and that obviously has a high concentration of construction.”
He and his co-authors calculated that there are not quite 1.1 million buildings in the city — 1,084,954, to be exact. After estimating the number of floors in each and doing some computer modeling, he calculated their total weight to be 1.68 trillion pounds. Then he factored in the pull of gravity and other factors to determine how much the city would sink.
Parsons said that some parts of the city are sinking faster than others. He mentioned areas along the East River in Queens and Brooklyn, as well as Coney Island, Jamaica Bay and the Rockaways. Most Manhattan skyscrapers are anchored to bedrock, which is “far less compressible” than soil.