Nav: Home

Next century will bring deep water to New York City

October 10, 2016

New York City can expect 9-foot floods, as intense as that produced by 2012's Superstorm Sandy, at least three times more frequently over the next century - and possibly as much as 17 times more frequently, according to a paper published today by scientists at Rutgers University, Princeton University and the Woods Hole Oceanographic Institution.

The paper was published in the Proceedings of the National Academy of Sciences.

The study is based on a combination of historical data and computer model projections performed by Ning Lin of Princeton University, Benjamin Horton and Robert Kopp of Rutgers University, and Jeff Donnelly of the Woods Hole Oceanographic Institution. The historical data consist of tidal gauge records taken from New York City, going back to 1856, and geological records from the same area going back two millennia. The model projections consist of Kopp's work on future sea-level models; Lin's work on future storm intensity; and the work of Horton, Kopp and Donnelly on historical sea levels and storm surges.

The scientists ask the question: How frequent will floods like that produced by Sandy be in the future? Earlier research led by Andra Reed, now a postdoctoral scholar at Rutgers, had shown a 20-fold increase in the frequency of extreme floods, primarily as a result of sea-level rise, between the historic period from 850 to 1850 and the late 20th century.

The historic sea-level rise was largely due to natural effects, like the slow sinking of the land in the mid-Atlantic region in response to the end of the last ice age; but over the late 20th century, human-caused climate change came to dominate sea-level rise.

In the paper published today, the authors report that floods as intense as Sandy's would have occurred about once every 400 years on average under the sea-level rise conditions of the year 2000, but that over the 21st century are expected to be about four times more probable due to an acceleration in the rate of sea-level rise.

"The grand answer is that things are going to get worse by 2100," says Horton, who is professor of Marine and Coastal Sciences in the School of Environmental and Biological Sciences. "If nothing changes with hurricanes, sea-level rise alone will increase the frequency of Sandy-like events by 2100."

But the size, intensity, and tracks of hurricanes may change. In the paper, Princeton's Lin combined historical climate data and modeling of future climate conditions and storm surges. She found that these changes may lead to a more modest three-fold increase in flood probability, but may also break badly against New York City, making Sandy's flood 17 times more probable.

"As we refine climate and hurricane dynamic models, we will have more accurate predictions that will allow planners to better design flood mitigation strategies," said Lin, the study's lead author.

The study built upon past work by Kopp, professor of earth and planetary sciences in the School of Arts and Sciences, estimating sea levels over the 21st century. "We ask, 'What is likely?' and 'What are the extremes?'" Kopp said. "We take into account factors that cause local sea level to vary from global sea level. And we've shown, through geological investigations, that our projections are consistent with the assumption that temperature and sea level will be related in the future as they have been over the past two thousand years."

Projections are not predictions and, Horton says, the spread between what's "likely" and "extreme" is an indication of the complexity of future projection. "Things are only going to get worse by 2100," Horton says. "It's just a question of how much worse it will get. There is no happy scenario."
-end-


Rutgers University

Related Sea Level Articles:

Researchers untangle causes of differences in East Coast sea level rise
For years, scientists have been warning of a so-called 'hot spot' of accelerated sea-level rise along the northeastern US coast, but understanding the causes has proven challenging.
Sea level as a metronome of Earth's history
Sedimentary layers contain stratigraphic cycles and patterns that precisely reveal the succession of climatic and tectonic conditions that have occurred over millennia.
Migration from sea-level rise could reshape cities inland
Researchers estimate that approximately 13.1 million people could be displaced by rising ocean waters.
Short-lived greenhouse gases cause centuries of sea-level rise
Even if there comes a day when the world completely stops emitting greenhouse gases into the atmosphere, coastal regions and island nations will continue to experience rising sea levels for centuries afterward, according to a new study by researchers at MIT and Simon Fraser University.
Climate change could trigger strong sea level rise
About 15,000 years ago, the ocean around Antarctica has seen an abrupt sea level rise of several meters.
Historical records may underestimate global sea level rise
New research from scientists at University of Hawai'i at Mānoa, Old Dominion University, and the NASA Jet Propulsion Laboratory shows that the longest and highest-quality records of historical ocean water levels may underestimate the amount of global average sea level rise that occurred during the 20th century.
Volcanic eruption masked acceleration in sea level rise
The cataclysmic 1991 eruption of Mount Pinatubo in the Philippines masked the full impact of greenhouse gases on accelerating sea level rise, according to a new study.
Pacific sea level predicts global temperature changes
Sea level changes in the Pacific Ocean can be used to estimate future global surface temperatures, according to a new paper in Geophysical Research Letters.
Climate change already accelerating sea level rise, study finds
Greenhouse gases are already having an accelerating effect on sea level rise, but the impact has so far been masked by the cataclysmic 1991 eruption of Mount Pinatubo in the Philippines, according to a new study led by NCAR.
As sea level rises, Hudson River wetlands may expand
In the face of climate change impact and inevitable sea level rise, Cornell and Scenic Hudson scientists studying New York's Hudson River estuary have forecast new tidal wetlands, comprising perhaps 33 percent more wetland area by the year 2100.

Related Sea Level Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".