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[00:00.68] New York City is slowly sinking.

[00:05.19] With the weight of its tall buildings, streets and people, the city is sinking at an average rate of 1 to 2 millimeters each year, a new study says.

[00:20.60] The sinking is called “subsidence.”

[00:25.12] That natural process happens everywhere as ground is compressed.

[00:31.76] But the study published in the publication Earth's Future in May sought to estimate how the huge weight of the city itself is hurrying things along.

[00:47.16] More than 1 million buildings are spread across the city’s five boroughs.

[00:55.39] The research team found that all those structures add up to about 1.5 trillion metric tons of concrete, metal and glass.

[01:10.27] That is equal to the mass of 4,700 Empire State buildings pressing down on the Earth.

[01:21.43] The rate of compression is different throughout the city.

[01:25.94] Midtown Manhattan's tall buildings, or skyscrapers, are largely built on rock, which compresses very little.

[01:37.62] But some parts of Brooklyn, Queens and downtown Manhattan are on looser soil and sinking faster, the study said.

[01:50.91] While the process is slow, parts of the city will eventually be under water, said Tom Parsons.

[02:01.00] He is the lead researcher of the U.S. Geological Survey.

[02:06.84] Making the problem worse is rising sea level.

[02:12.16] “The ground is going down, and the water’s coming up.

[02:17.47] At some point, those two levels will meet,” said Parsons.

[02:24.11] Parsons and his team of researchers reached their conclusions using satellite imaging, data modeling and mathematical calculations.

[02:37.92] It will take hundreds of years before New York becomes Venice.

[02:43.76] The city in Italy is famously sinking into the Adriatic Sea. But parts of New York are more at risk.

[02:55.19] Parsons said that Manhattan is at risk because of the borough’s large weight.

[03:02.36] “The average elevation in the southern part of the island is only 1 or 2 meters above sea level — it is very close to the waterline, and so it is a deep concern.”

[03:18.03] The ocean is rising at a similar rate that the land is sinking.

[03:24.41] So the Earth's changing climate could speed up the process for parts of the city to go under water.

[03:33.71] “It doesn’t mean that we should stop building buildings…,” Parsons said.

[03:39.28] "The purpose was to point this out in advance before it becomes a bigger problem.”

[03:47.79] Already, New York City is at risk of flooding because of large storms.

[04:00.00] Storms like Sandy in 2012 caused the ocean to expand inland and flooded neighborhoods after a lot of rain.

[04:08.77] Andrew Kruczkiewicz is a senior researcher at Columbia University’s Climate School, who was not involved in the research.

[04:20.19] Kruczkiewicz said the study’s findings could help inform policy makers as they plan ways to slow the rising seas.

[04:31.08] “We can’t sit around and wait..,” he added.

[04:36.12] New York City is not the only place sinking.

[04:40.37] San Francisco, California, is also at risk because of pressure on the ground and the area’s active earthquakes.

[04:51.26] In Indonesia, the government is preparing for a move from Jakarta, which is sinking into the Java Sea.

[05:00.29] The government is building a new capital being constructed on the higher ground of an entirely different island.