Sea Levels Rising Rapidly Around World, NY at Highest Risk in US

Hundreds of millions of people around the world can be threatened by the rising seas.
Sea Levels Rising Rapidly Around World, NY at Highest Risk in US
The New York City skyline is viewed in New York City on Oct. 19, 2009. New York's average sea level rise in the past 23 years is higher than the global average. (Spencer Platt/Getty Images)
8/30/2015
Updated:
8/31/2015

Over the past 23 years, most places in the world have experienced rising sea levels, according to Josh Willis, project scientist for NASA’s Jason-3 Mission, which measures sea level rise from space.

In a short video called “Watching Rising Seas From Space,” Willis talks about the global trend of rising sea levels, which have gone up by almost 3 inches since 1992.

More than 90 percent of heat in greenhouse gases are absorbed by the oceans and that causes seawater to expand, which helps drive sea level rise, he said.

“As water heats up it takes up more room; this drives sea level rise and in addition as glaciers and ice sheets are melted, extra water is added to the ocean, just like when you turn on your faucet in the bathtub,” Willis explained.

Western Pacific Rapidly Rising

Hundreds of millions of people around the world live on coastlines that can be threatened by the rising seas, and this is particularly evident in the western Pacific where sea levels have been “rising very rapidly.”

Heat gets pushed across the Pacific by large ocean currents like el Niño, which occurs every three or four years. According to the National Ocean and Atmospheric Administration (NOAA), the trade winds push warm surface water to the west Pacific causing “important consequences.”

One of the consequences is increased rainfall across the southern tier of the United States and in Peru, resulting in severe flooding and drought in the west Pacific. The Pacific Decadal Oscillation is another el Niño-like pattern of robust current that waxes and wanes every 20 to 30 years having significant impacts on coastlines.

But these conditions are not uniform around the world, according to NASA’s team of scientists in a recent news release.

“Sea level along the West Coast of the United States has actually fallen over the past 20 years because long-term natural cycles there are hiding the impact of global warming,” said Willis in the news release.

However, he expects the sea level to rapidly rise on the West Coast over the next 10 years as the region recovers from the temporary drop in level.

New York Higher Than Global Average

There hasn’t been a shortage of water along the coast of New York though. The state estimated 1,850 miles of tidal shoreline has been experiencing unprecedented sea level rise.

In New York, according to the New York Department of Environmental Conservation (NYDEC), the sea level has risen at least a foot since 1900. Between 2009 and 2010, the level north of New York City rose an unprecedented 5 inches, according to an article in Nature Communications.

New York City is situated along 520 miles of coastline, with an extensive underground infrastructure. It is listed as America’s largest coastal community prone to the risks of climate change in a NOAA fact sheet.

Because there are no easy evacuation routes, New York City is particularly vulnerable to coastal storms and sea level rise. In a report prepared by the Land Use Law Center at Pace University School of Law, it is predicted that New York City’s mean annual temperatures will increase by 4 to 7.5 degrees Fahrenheit by the end of the century. The report projects an increased precipitation of 5 to 10 percent and sea level rise of 12 to 23 inches.

By 2100, NYDEC predicts sea levels could be 18 to 50 inches higher than they are today along New York’s coastlines with a potential to even rise as high as 75 inches.