Local solutions against the risks associated with sea level rise remain to be found.
- Several neighborhoods in New York are sinking into the ground between one and two millimeters per year
- A problem in parts of the city like lower Manhattan, Queens, and Brooklyn built at sea level
- In the question: the weight of the buildings of the city, in particular, the skyscrapers
According to a study published in Earth’s Future, entire neighborhoods in New York are collapsing under the weight of buildings. A real threat is in high-density areas built at sea level like lower Manhattan, Queens, and Brooklyn.
Researchers from the American Geological Institute and the University of Rhode Island have calculated that subsidence averages between one and two millimeters per year, although locally it can be significantly more pronounced.
Why New York is sinking a few millimeters a year
In itself, land subsidence is not a rare phenomenon. The ground is composed of various materials soaked with more or less water. Depending on the weight of what is built on the surface, and the climate, the ground can more or less deform over time. However, it is rare that this takes place on such a shortened scale.
If New York was built inland, sinking it into the ground probably wouldn’t be a problem. But we are talking about a city located on the coast, which is already feeling the effects of rising sea levels. With this subsidence, parts of the city could find themselves plagued by more frequent floods if nothing is done. do.
The researchers explain: “New York is facing significant challenges around flooding; the threat of rising sea levels there is between 3 and 4 times higher than the average on the Atlantic coast of North America”. We are talking about a city where some 8.4 million inhabitants are still concentrated…
And to continue: “New York is emblematic of growing coastal cities around the world that are bemoaning land subsidence, which means that finding solutions to the growing threat posed by flooding is becoming a shared global challenge”.
A study by the American Geological Institute in 2021 notably made a similar observation in San Francisco, in the United States. Alas, beyond the observation, the researchers do not dare to outline any solution. Which does not mean that there is no precedent in the world.
The Netherlands, in particular, is largely built below sea level. Following catastrophic floods, the Dutch government implemented the “Delta Plan” between 1954 and 1997. Today, the south coast of the country contains the largest collection of water defenses in the world. The infrastructure should also soon be reinforced in the face of rising sea levels.