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Tuesday, March 11, 2008

Government Reports Warn Planners on Sea-Rise Threat to U.S. Coasts

Blogger's note: this a very long overdue article.

by Cornelia Dean, New York Times, March 11, 2008

A rise in sea levels and other changes fueled by global warming threaten roads, rail lines, ports, airports and other important infrastructure, and policy makers and planners should be acting now to avoid or mitigate their effects, according to new government reports.

While increased heat and “intense precipitation events” threaten these structures, the greatest and most immediate potential impact is coastal flooding, according to one of the reports, by an expert panel convened by the National Research Council, the research arm of the National Academy of Sciences.

Another study, a multiagency effort led by the Environmental Protection Agency, sounds a similar warning on infrastructure but adds that natural features like beaches, wetlands and fresh-water supplies are also threatened by encroaching saltwater.

The reports are not the first to point out that rising seas, inevitable in a warming world, are a major threat. In a report last September, the Miami-Dade County Climate Change Task Force noted that a two-foot rise by the year 2100, the prediction of the United Nation’s Intergovernmental Panel on Climate Change, “would make life in South Florida very difficult for everyone.”

But the new reports offer detailed assessments of vulnerability in the relatively near term. Both note that coastal areas are thickly populated, economically important and gaining people and investment by the day, even as scientific knowledge of the risks they face increases. Use of this knowledge by policy makers and planners is “inadequate,” the academy panel said.

“It’s time for the transportation people to put these things into their thought processes,” Henry G. Schwartz Jr., the chairman of the Research Council panel, said in an interview.

The 218-page academy report was issued Tuesday, and is available at

Noting that 60,000 miles of coastal highways are already subject to periodic flooding, the academy panel called for policy makers to survey vulnerable areas — “roads, bridges, marine, air, pipelines, everything,” Dr. Schwartz said — and begin work now on plans to protect, reinforce, move or replace on safer ground. Those tasks will take years or decades and tens of billions of dollars, at least, he said.

“We need to think about it now,” said Dr. Schwartz, a member of the National Academy of Engineering.

The multiagency report, a draft assessment, is intended to help policy makers do just that. The 800-page draft was posted online last month for public review at It focuses on the area from Montauk Point on Long Island to Cape Lookout, N.C.

Produced by a collaboration among agencies that included the United States Geological Survey, the National Oceanographic and Atmospheric Administration and the Department of Transportation, the report offers three estimates for sea-level rise by 2100: about 16 inches a century, a rate it said had already been exceeded; about two feet, an estimate many scientists regard as optimistic; and up to three feet, which the report says would be catastrophic for wetlands and other coastal features but that is “less than high estimates suggested by more recent publications.”

The academy report cited similar estimates.

The multiagency report cited the Port of Wilmington in Delaware as an example. The report says that if the sea level rises by two feet or even a bit less, 70 percent of port property will be affected.

Meanwhile, it says, such a rise in sea level would leave almost 2,200 miles of major roads and almost 900 miles of rail lines in Maryland, Virginia, North Carolina and the District of Columbia “at risk for regular inundation.”

The academy report made similar points, noting, for example, that airports in many large coastal cities are built in tidal areas, often on fill, making them “particularly vulnerable.” In the New York metropolitan area, Newark Liberty International Airport and La Guardia Airport are especially at risk, Dr. Schwartz said.

Some experts have suggested that additional fill could keep pace with rising water, just as many beaches are kept alive today with periodic infusions of sand pumped from offshore. But S. Jeffress Williams, a coastal expert at the geological survey and an author of the multiagency report, noted in an interview that necessary quantities of high-quality fill might not be available where they were needed. In that case, he said, policy makers would have to consider constructing immense systems of coastal armor or accept the need for “strategic retreat.”

As a first step, the academy report said, transportation officials must realize that climate patterns that prevailed in the past “may no longer be a reliable guide for future plans.” Instead, it said, they should incorporate climate change into their plans for capital improvements, maintenance schedules, emergency preparedness and so on.

The panel also recommended changes in the National Flood Insurance Program, a federally subsidized program for coastal properties. The report said the maps the program used in setting rates did not reflect the influence of climate change.

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