Like many New Yorkers, Radley Horton often frets about tomorrow's
weather. Unlike many, it's his job. A scientist at NASA's Goddard
Institute for Space Studies (GISS) and coauthor of a forthcoming
study on the effects of climate change in New York City, he is
particularly concerned about an often-overlooked aspect of global
warming: bigger, stronger storms.
"It's not a linear relationship," he says on a subway ride to
Manhattan's South Ferry station, which would be mostly underwater in
a Category 2 hurricane. "A little bit warmer sea surface equals the
potential for a lot stronger storm." And feeding off the greater
ocean warmth, full-blown hurricanes may arrive at New York City with
By 2050, stronger storms and rising sea levels may make the flood
that previously hit once every 100 years a once-in-20-years event,
according to GISS. With a possible three-foot sea level rise by
2100, flooding could occur every four years. "Our old ideas about
climate may have to change," he says. "We need to be open to all
Even as high-profile politicians like California Gov. Arnold
Schwarzenegger and New York Gov. George Pataki pledge to reduce
their states' carbon "footprint," cities like New York and London -
and entire countries like the Netherlands - are moving to adapt to
long-term climate change.
With slogans like, "Why should you worry about a hurricane? It's
not like you live on an island" and a tripling of storm shelters
since Katrina, New York City's Office of Emergency Management has
prepared for at least some of the short-term possibilities.
But even before Katrina, the city's Department of Environmental
Protection (DEP), which manages the city's freshwater supply and
wastewater - 13,000 miles of pipe, total - formed a task force with
GISS to look at the long-term effects of climate change.
Among other things, the DEP was concerned by the damage storm
surges might inflict on a city surrounded by water. Although city
officials declined to discuss concrete solutions for this article
saying they were still in the "assessment" phase, scientists foresee
potential fixes ranging from raising key infrastructure and building
dikes, to flood gates and temporary seals over tunnel entrances. One
group proposes raisable flood barriers large enough to protect all
of Manhattan Island.
Sea levels have risen almost a foot in the past century, partly
because of ice melt and thermal expansion (warmer water has more
volume), and partly because of naturally occurring land subsidence
of the Northeast. In the same period, area temperatures have risen
nearly 2 degrees F. About two-thirds of that increase occurred in
the past 30 years and sea-level rise has accelerated in the past
decade. "The core body of knowledge has solidified" on climate
change, says Cynthia Rosenzweig, the lead GISS scientist on the
climate-change task force. "We're moving into a solution phase."
But possible solutions - and how to pay for them - are still "big
question marks," says Gary Heath, director of bureau operations and
environmental analysis at the DEP. Although antiflooding
technologies are basic and well established, implementing them in a
city as old and crowded as New York is no simple task.
Elevating roads, for example, sends more runoff into subway
grates. Water pumped out of subway tunnels - already some 14 million
gallons daily - goes into sewer systems that might be overtaxed by
rainwater. "You solve one problem and you create another," says
Madan Naik, chief structural engineer of New York City Transit.
"It's got to be a collaborative effort, whatever we do."
Much of this city of 8 million, the largest and most densely
populated major city in the US, is only 10 feet above sea level. The
potential 30-foot storm surge accompanying a Category 3 hurricane
would flood large swaths of south Brooklyn, parts of Queens, Staten
Island, and Manhattan below Canal Street, including the World Trade
Center site - 100 square miles total. …