The New New Amsterdam

by Dean Olsher

Tom Abdallah, chief engineer of the New York City subway system, in the South Ferry station. (photo: Donna Ferrato)

Tom Abdallah, chief engineer of the New York City subway system, in the South Ferry station. (photo: Donna Ferrato)

In a part of New York City called Battery Park, on the lower end of Manhattan, lies the South Ferry subway station. It’s the newest one in the city, and when Superstorm Sandy hit in 2012, it was completely inundated.

Tom Abdallah is the chief environmental engineer for the New York City subway system. It’s his job to make sure that never happens again.

“Your heart sank to the middle of your stomach when we saw the devastation, and that all that hard work would go down the drain,” Abdallah says. “But we’re at it again and we’ll put it back together better than it was before.”

Abdallah walks behind a temporary wall of the new station to a feature he helped to design. It’s a mosaic map of the old city, back in the mid-1600s when it was still called New Amsterdam. The map is at the top of a stairway leading up from the subway track about 65 feet below.

The stairs in the South Ferry station during Sandy (above) and today (below)

Stairs in the South Ferry station during   Sandy (above) and today (below)
photos: Donna Ferrato (bottom), courtesy of Tom Abdallah (top)

After Sandy, the floodwaters came as high as the bottom of that very map, covering the lower tip of Manhattan. It was a spooky parallel to what was going on in real life aboveground, since water from the ocean completely covered the southernmost end of Manhattan.

After studying the map, Abdallah leads the way down to the platform to see the current state of the cleanup. They’ve made a lot of progress.

“It’s kind of eerie to be on a station platform that’s not inundated with a lot of people,” Abdallah says.

As he walks, he passes large ventilation fans that his crew installed.

He says suction caused by trains moving through tunnels naturally ventilates most of the subway, but here in the South Ferry station there was an HVAC system.

“That was completely destroyed” by Sandy, he says. “That’s why we have these fans running. We want to keep it as moisture-free as we can so that mold doesn’t develop.”

Back above the South Ferry station is Battery Park. There is no place that better tells the story of New York City’s relationship to the sea.

It was there that just over 400 years ago Henry Hudson sailed his ship, the Half Moon, into the natural harbor. That meant calm waters for shipping, and a perfect place to locate a settlement.

Battery Park lies at the southern tip of Manhattan. (photo: Donna Ferrato)

Battery Park lies at the southern tip of Manhattan. (photo: Donna Ferrato)

Now, the very factors that made this place safe are the source of the trouble New York has been experiencing as a result of Sandy.

It was in Battery Park a year ago that the floodwaters caused by Hurricane Sandy overwhelmed the entire lower tip of Manhattan.

Malcolm Bowman is an oceanographer who runs the storm surge group at SUNY Stony Brook. In Bowman’s vision of the future, New York will, in a way, be New Amsterdam once again.

In 2008, Mayor Bloomberg appointed Bowman to the New York City Panel on Climate Change. But Bowman is frustrated by New York City’s response to Sandy.

“The buzzword around town, the mantra, is ‘resilience,’” Bowman says. “And what does resilience mean? In this context it means ‘Look, it’s inevitable. It’s going to happen again, but let’s just hope that next time around we’re better prepared.’ That’s resilience.”

Bowman says that sounds like admitting defeat.

“It’s a statement that we cannot protect the city so that this never happens again,” he says.

Perhaps New York has been a little complacent because of the natural features. Lots of bedrock below all of those skyscrapers makes it well positioned to withstand rising sea levels.

“There was a feeling of invincibility, really,” Bowman says. “That although New York City is obviously a city built on the water’s edge, that we were safe, we were protected between the coastlines of Long Island and New Jersey and no hurricane could possibly hit here.”

Hurricanes are not the only threat. Other storms, just as dangerous, are now a part of life.

“The quality that made this spot so attractive to Henry Hudson—the fact that it is a protected harbor—is the same quality that leaves it so vulnerable to storms,” says Roland Lewis, the president of the Metropolitan Waterfront Alliance.

Lewis says the same natural features that keep storms out can also keep water in.

“If you look at a map, you see the shore of New Jersey, you see Long Island, and they point toward the New York Harbor,” he says. “And when the cards line up as they did for a storm even like Sandy, that attribute of being a protected harbor, having a small opening, becomes a liability, and water is forced in.”

In the case of Sandy, that water was forced into basements and ground floors of buildings. In some parts of lower Manhattan, the floodwaters were 6 feet and higher.

Because of Sandy, New York has to once again renegotiate its lease with the sea.

The city is getting high marks around the country for its leadership on dealing with rising sea levels. In June, the Bloomberg administration responded to Sandy with a 438-page plan called “A Stronger, More Resilient New York.”

The Bloomberg Plan calls for sealing up tunnels and strategically positioning a series of levees and dikes at vulnerable points around the city. Roland Lewis describes this as “dry-proofing.”

“And then there’s wet-proofing,” Lewis says, walking through Battery Park. “The idea that you can let water in; let water out. And parks are wonderful places for that. The harm will be minimal, or expected, if there’s flooding.”

It is a sunny fall day in the park. Suddenly, Lewis finds himself standing in front of something he did not expect. A wild turkey has taken up residence in Battery Park, and park workers have adopted it.

“Zelda!” One of the workers calls out. “Zelda, come here!”

The turkey continues walking right at Lewis. She thinks he has food, maybe.

“Zelda!” yells the park worker.

The scene provokes the feeling that nature is trying to take back the city. That’s certainly how it has felt in Breezy Point in the year since Sandy.

Breezy Point is a beach community in the Rockaways. With the Manhattan skyline about 20 miles off in the distance, it looks as if it’s in another state. But in fact, the point is still within New York’s city limits.

Rebuilding in Breezy Point still had a long way to go in the fall of 2013. (photo: Dean Olsher)

Rebuilding in Breezy Point still had a long way to go in the fall of 2013.  (photo: Dean Olsher)

It was at Breezy Point that water from Sandy came into contact with electrical wires and caused a fire that burned 126 homes to the ground. A year later, all that is visible is one bare foundation after the next. The rebuilding is only beginning.

It is from Breezy Point that Malcolm Bowman’s vision for New York’s future begins, modeled after projects undertaken in Europe.

“Go to London and see the Thames River barrier,” Bowman says. “Go to the Netherlands and see the Delta project.”

The Delta project resulted from a storm surge in the North Sea in 1953, causing widespread flooding in the Netherlands, Belgium and the U.K., and leaving about 1,800 people dead. The Dutch response included building storm surge barriers—huge walls in the sea that keep out the ocean.

Malcolm Bowman envisions two similar barriers for New York City. One of them would stretch from Breezy Point about five miles across the harbor, over to Sandy Hook in New Jersey. It would do triple duty: as a bridge for cars, and also for rail tracks, and as a gate that would open and close as necessary to keep the ocean away from New York and northern New Jersey. It would cost about the same as the Bloomberg plan, which Bowman says is necessary but not sufficient.

One argument against storm surge barriers is that they may be too ambitious, and not everyone is convinced they would work. Roland Lewis says he thinks they should be tested.

Bowman, though, is disappointed that the Bloomberg plan specifically excludes them.

“That surprises me,” he says. “Because Bloomberg, his first degree is in engineering.”

For years, long before Sandy, Bowman has pushed for these barriers. As a result, he has been called a prophet: Noah, in particular.

When it comes to his idea of walling out the ocean to protect New York City from future storms, he does seem like a lone voice in the wilderness.

“Some of my colleagues say, ‘Look, Malcolm, the city is eventually doomed. Let’s start planning a retreat. Let’s start heading for the hills,’” Bowman recalls. “And I say, ‘Look, that’s never going to happen. That’s not realistic.’”

Bowman looks to the Netherlands for inspiration.

“You can’t tell the Dutch to run for the hills,” he says. “There are no hills. The whole country is flat as a pancake. And Germany and France and Belgium don’t want 20 million refugees.”

So, Bowman says, the Dutch have decided to “stand and fight.”

“They’ve decided, ‘That’s in our genes, that’s in our history,’” Bowman says. “’So we’re going to strengthen our coastal resources, we’re going to do what’s necessary, we’re going to train our engineers to be the best in the world, and if we get 150, 200 years more, then we’ve done well.’”

And New York should do the same, Bowman says. To retreat is to betray the trust of New York City’s children.

 

Dean Olsher is a writer, broadcaster and composer based in New York City. 

Emily Haavik edited this story for the web.

Listen to an audio version of this story

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Future Sea Level

A break with the past

In the late 1990s, a dramatic event surprised and disturbed glaciologists around the world, increasing concern that global warming could cause Earth’s great ice sheets at the north and south poles to disintegrate rapidly and catastrophically. A frozen stream of ice in the Jakobshavn Glacier on Greenland’s west coast suddenly accelerated seaward. Already one of the world’s fastest moving glaciers, Jakobshavn doubled its speed.

jakobshavn

Jakobshavn glacier in 2013
Photo: Gretel Ehrlich

Mountainous blocks of ice broke off Greenland’s perimeter at a furious rate, clogging a 35-mile long fjord with icebergs bigger than aircraft carriers. Fortunately, Jakobshavn settled down several years later. But before it did, the glacier had expelled tens of billions of tons of ice into the Atlantic.

Scientists aren’t sure why Jakobshavn sped up, or tapered off later. They haven’t  been able to calculate the top speed that an ice stream like Jakobshavn could achieve. Nor can they specify the limit of how much mass such streams of ice in Greenland or Antarctica could cast into the sea. They’d dearly like to know, as many researchers believe the accelerated flow of solid ice in ice streams could dramatically increase the rate of sea level rise.  Until these questions are resolved, some researchers consider it possible that sea level rise later this century could be many feet.

Global warming basics

Earth is getting hotter. The planet has heated up by around 1.5 degrees Fahrenheit (0.8 degree Celsius) since the 1880s. When the oceans heat up, their water expands and creeps up shorelines. Higher temperatures also threaten mountain glaciers and the huge ice sheets at Earth’s north and south poles. Since extra heat also cranks up evaporation and precipitation, sometimes in the form of snow that compensates for melting, higher temperatures don’t necessarily always make glaciers shrink.

CO2 graphIn practice, though, scientists have discovered that all the world’s major glaciated mountain ranges including the Andes, the Himalayas, the Swiss Alps and the mountains of Alaska are losing ice. The continental-size ice sheets of the poles are shedding massive amounts of mass into the sea. As a result, sea level has gone up by about 4.5 inches (11 centimeters) since 1950. The rate at which sea level is increasing appears to be going up, though researchers can’t be sure until more time has passed.

About 40 percent of the world’s inhabitants work and farm and sleep within about 50 miles of a coastline. The sea laps the land of eight of the world’s top ten cities. As the sea rises, many of these people are threatened with increased flooding, storm damage and salt intrusion into groundwater. Billions of dollars of property and millions of lives are at risk.

How fast and how high might sea level grow in the future? Government planners and residents of coastal regions are among the many people who could plan better if they knew the answer. Scientists have made estimates of future sea level. But their results are uncertain because the task is complicated by the numerous factors that influence sea level rise.

Earth’s ice

Ice occurs naturally in various forms in many parts of the world. Each kind has its own particular relationship to global warming and sea level. When viewed from space, Earth’s most obvious feature, after the oceans, is, a vast white wintertime band of snow covering northern Asia, Europe and North America. Global warming will reduce the amount of land covered in snow. But that melted snow will have virtually no impact on sea level. That’s because the layer of snow is thin, and the volume of water in snow is dwarfed by the vastness of oceans.

icebergs

Icebergs near Greenland
Photo: Gretel Ehrlich

The second most noticeable form of frozen water on Earth is sea ice. Sea ice, as the name suggests, is water frozen on the ocean’s surface, generally near the poles. The amount of sea ice varies with the seasons. At its maximum extent, such ice covers about 10 million square miles of water, an area about the size of ten Australias. The amount of sea ice in the Arctic has been declining steadily for at least as long as systematic satellite monitoring began in the late 1970s. Many researchers predict that the Arctic will be virtually free of sea ice in summers before the middle of this century; perhaps much sooner.

The disappearance of sea ice will not alter sea level. That’s because sea ice floats, just like ice cubes in a drink. When a soda on the rocks warms up, the level of the surface remains fixed. (However, the loss of sea ice will have numerous other detrimental effects. Sea ice reflects sunlight back into space, whereas ocean water absorbs most sunlight that hits it. Less sea ice means a warmer Arctic. The temperature differential between the Arctic and equatorial regions, a major force behind Earth’s weather patterns, will be muted.

Moreover, sea ice performs important roles in polar ecosystems. Marine mammals such as some seals and polar bears depend on it as a platform for hunting and resting.  Many of the marine plants that form the foundation for the polar food chain, known as phytoplankton, also depend on sea ice for part of their life cycle.)

Unlike sea ice, the huge ice sheets of Antarctica and Greenland rest on land (or, in some cases, the seafloor). Sea level does rise when they melt. The ice sheets occupy less area than sea ice or snow, but they’re radically thicker (more than a mile, or about 1.6 kilometers, from top to bottom in places). All together, the polar ice sheets hold enough water to lift sea level by about 250 feet (76 meters). Mountain glaciers also raise sea level as they recede, which they’re doing, at a spectacular rate. But mountain glaciers hold only a small fraction of the water stored in polar ice sheets: only enough to raise sea level by about 2 feet (0.6 meters).

Unlike ice cubes

Because polar ice sheets are so massive, the rate at which they might melt has received concerted scientific attention. Still, many questions remain. If ice sheets behaved like an ice cube dropped out of a freezer tray on a summer day, predicting how fast they’d waste away—and how fast sea level would rise—would be relatively easy.

pullquote_coastIce cubes melt from the outside inward. As the exterior dribbles off, inner ice appears in an orderly fashion, like layers peeled off an onion. To predict the fate of ice melting this way requires taking into account factors like air temperature and the movement of air currents. Scientists know how to perform such calculations for ice cubes as well as for ice sheets. Researchers have estimated, roughly, that if all the world’s glaciers melted this way, sea level rise by about 15 inches (0.4 meters) by the end of the century. Sea level rise of this magnitude can’t be ignored, but it’s relatively small, and it would occur over many decades.

But, while behaving in part like ice cubes, ice sheets also waste away in a manner unlike any ice cube: from the inside out. Frozen ice streams convey an ice sheet’s bulk from the interior to the perimeter at the sea, sometimes hundreds of miles away.  At the edge of the ice sheet, great blocks shear off and fall into the water. An ice sheet flowing this way could lose volume much faster than one that suffers surface melting alone.

Alternate Approaches

There are two primary means of forecasting future sea level. In one, scientists create a mathematical model of sea level that takes into account how much water will expand and how much glaciers will grow or shrink. This method requires a detailed understanding of factors like how heat penetrates into the ocean’s depths, how changes in air temperature influences precipitation and, of course, the behavior of warming glaciers.  Researchers have created such models. But they suffer from uncertainty about how Earth’s complex parts work and relate to each other.

Blowing Rocks, Florida

Blowing Rocks Preserve, Florida

The other major way that scientists try to predict future ocean inundation is by studying sea level in Earth’s past, when the planet was as warm or warmer than today. For the last two million years or so, Earth has cycled more than a dozen times between ice ages and warm periods. The last ice age ended about 12,000 years ago. Scientists think these temperature swings are controlled in part by changes in Earth’s orbit around the sun. During an ice age, billions of tons of water freezes on mountaintops and at the poles.  Sea level falls hundreds of feet. During a warm period, in contrast, this ice melts, ocean basins swell with the extra liquid, and the seas rise.

Climate researchers are especially interested in how high the sea rose during previous warm periods, prior to the most recent ice ages. Several such epochs have been hotter than today, making them possible analogs to our warmer future. The most recent warm period, about 100,000 years ago, was 2 to 4 degrees Fahrenheit (1 to 2 degrees Celsius) warmer than today. Many scientists believe that sea level was 15 to 20 feet higher then.

Choosing whether to act

Earth’s temperature will rise sharply unless steps are taken to reduce significantly the amount of fossil fuel burned to make electricity, power vehicles and to heat homes. We’ll have to make heroic efforts to prevent global temperature from reaching or surpassing that of the last warm period.

If Earth does get that hot, many scientists believe that sea level will rise to the level it reached during that earlier spell. They readily admit, however, that they can’t predict how quickly the sea would go up.

They’ve uncovered evidence that within the past 20,000 years sea level has gone up at a rate as fast as 12 feet (4 meters) per century. However they can’t say if global warming could cause sea level to rise that quickly in the future.

 

Dan Grossman is print journalist and radio and web producer. You can see more of his work on the extensive Sea Change website.

 

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The melting of Greenland

greenland_map_v2

Neal Conan – former NPR host and correspondent – went to Greenland for a closer look at the island’s melting ice. One of his guides was acclaimed science and nature writer Gretel Ehrlich.

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What IPCC’s climate report says about rising sea levels

Lauren Sommer, BURN Contributor

No one was too shocked by the latest climate projections released in the Intergovernmental Panel on Climate Change’s (IPCC) fifth report on Friday. The United Nations-created group is responsible for a sort of climate change “master doc,” collating studies from around the globe into a general consensus with the help of thousands of scientists.

 What did they find? Global temperatures are on the rise and we’re to blame. Or, in scientific speak, the panel said it’s “extremely likely” (greater than 95 percent certainty) that the warming is primarily due to human influence (burning fossil fuels and pumping carbon into the atmosphere). “There is a need for us to reduce emissions of greenhouse gases substantially if we really want to stabilize the Earth’s climate and I hope this is a message that the world will receive and accept,” said IPCC chairman Rajendra Pachauri.

IPCCchart1One topic did grab headlines: rising sea level. On average, it’s already gone up about seven inches since 1900, but the rate of change is expected to speed up. Under a worst-case scenario with unchecked greenhouse gas emissions, sea levels could rise 20 to 38 inches by the end of the century. That’s higher than the IPCC assessed in its last report six years ago, which put it from 10 to 23 inches.

Why the difference? It has to do with the two different factors that cause sea level rise. One is based on a basic tenet of physics: as water gets warmer, it expands. That’s caused about 40 percent of the sea level rise they can account for over the last decade.

The other cause of sea level rise is a little trickier for scientists to sort out. Glaciers and the Greenland and Antarctic ice sheets contain massive amounts of water, and they’re melting. That makes the ice sheets the “ticking time bombs” of climate change, according to some. Complete loss of the Greenland ice sheet, something the report says is possible with sustained warming over a millennium, would cause sea levels to rise by 23 feet.

IPPCchart2

The Greenland ice sheet is losing ice at a faster and faster pace, but in its previous report, the IPCC excluded some of that information from its sea level rise projections, saying not enough was known about the melting process to model it accurately. The state of the science has improved, the panel says, hence the jump in the numbers.

Other studies in the scientific community put sea level rise projections even higher. The IPCC acknowledged that, but found “there is no consensus currently in the scientific community about these very high sea level projections over the next 100 years,” according to Thomas Stocker, co-chair of the IPCC working group that released the report.

As was seen with Superstorm Sandy, the economic cost of storm surges and flooding runs into the billions and may only be a taste of what’s predicted for New York City and other places around the globe. More details about the sea level rise scenarios and the strategies to reduce carbon emissions are expected as the IPCC rolls out the rest of its assessment over the next year.

Lauren Sommer reports on environment, science and energy for KQED Public Radio in San Francisco. All graphics from IPCC.

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