Excerpts from the first in a series of Reuters’ article on sea level rise. Click here to read the full article below.
By Ryan McNeill, Deborah J. Nelson and Duff Wilson
Sept. 4, 2014
…For this article, Reuters analyzed millions of data entries and spent months reporting from affected communities to show that, while government at all levels remains largely unable or unwilling to address the issue, coastal flooding on much of the densely populated Eastern Seaboard has surged in recent years as sea levels have risen.
These findings, first reported July 10, aren’t derived from computer simulations like those used to model future climate patterns, which have been attacked as unreliable by skeptics of climate change research. The analysis is built on a time-tested measuring technology – tide gauges – that has been used for more than a century to help guide seafarers into port.
Reuters gathered more than 25 million hourly readings from National Oceanic and Atmospheric Administration tide gauges at nearly 70 sites on the Atlantic, Gulf and Pacific coasts and compared them to flood thresholds documented by the National Weather Service.
The analysis was then narrowed to include only the 25 gauges with data spanning at least five decades. It showed that during that period, the average number of days a year that tidal waters reached or exceeded flood thresholds increased at all but two sites and tripled at more than half of the locations.
The methodology was adapted from those used by researchers at NOAA and Old Dominion University in Norfolk, Virginia. Reporters sought their input on how to analyze the data and how to present the findings.
Since 2001, water has reached flood levels an average of 20 days or more a year in Annapolis, Maryland; Wilmington, North Carolina; Washington, D.C.; Atlantic City, New Jersey; Sandy Hook, New Jersey; and Charleston, South Carolina. Before 1971, none of these locations averaged more than five days a year. Annapolis had the highest average number of days a year above flood threshold since 2001, at 34. On the Delmarva Peninsula, the annual average tripled to 18 days at the Lewes, Delaware, tide gauge.
…In Charleston, a six-lane highway floods when high tides prevent storm water from draining into the Atlantic, making it difficult for half the town’s 120,000 residents to get to three hospitals and police headquarters. The city has more than $200 million in flood-control projects under way.
…Engineers say there are three possible responses to rising waters: undertake coastal defense projects; adapt with actions like raising roads and buildings; or abandon land to the sea. Lacking a national strategy, the United States applies these measures haphazardly.
Sea level rise has become mired in the debate over climate change. And on climate change, the politically polarized U.S. Congress can’t even agree whether it’s happening.
…Congress actually recognized global warming way back in 1978 with passage of the National Climate Program Act. The law aimed to “assist the Nation and the world to understand and respond to natural and man-induced climate processes and their implications.”
But after three decades and more than $47 billion in direct federal spending on climate change research, Congress hasn’t passed a major piece of legislation to deal specifically with the effects of rising sea levels.
“In the U.S., you have best data set on what’s happening in the world, and yet it’s not used in public policy,” said Robert Nicholls, professor of coastal engineering at the University of Southampton in England and a contributor to the U.N.-sponsored Intergovernmental Panel on Climate Change. “You say you don’t believe in global warming. But sea levels have been rising for 100 years in Baltimore.”
…NASA scientist William Krabill and his team have flown research missions from there aboard aircraft with laser technology to measure changes in the Greenland ice sheet, 1,000 miles long, 400 miles wide and up to 2 miles thick. The data they have collected since 1991 has produced evidence that the ice covering Greenland is melting. “Any glacier we have visited in Greenland over the last 25 years is thinning,” Krabill said. “It’s thinning faster five years ago than when we visited 25 years ago.” They’ve found the same thing is happening to Antarctica’s ice sheet – seven times larger than Greenland’s. Their discoveries underpin predictions of rising seas for decades to come.
…New York City is planning a $20 billion mix of defense and adaptation measures – most notably, construction of “The Big U,” a 10-mile (16-km) fortress of berms and movable walls around lower Manhattan. Mayor Bill de Blasio’s office says three-quarters of the money needed over the next decade is already in hand from federal, state and local sources.
…“It’s becoming more and more competitive for federal funds in terms of protecting communities,” said Curtis Smith, a planner with the Accomack-Northampton Planning District.