In New York City, 10 of 17 power plants sit in a floodplain that could become more saturated in the next half-century, city official Adam Freed told the Senate Energy and Natural Resources Committee. In south Florida, a rise of 6 inches of seawater could cripple half of the area's flood-control capacity, said Florida Center for Environmental Studies director Leonard Berry. And in Louisiana, lawmakers are worried about Highway 1 -- a thin roadway vulnerable to inundation that links to some of the nation's richest oil and gas resources. "The key problem is that rising seas raise the launchpad for coastal storm surges and tilt the odds towards disaster," said Ben Strauss, a scientist at Climate Central, at the committee hearing. "Just a few extra inches could mean the difference to flood a family's basement -- or New York City's subway system, disabling it for months."
Much of the hearing focused on previously released scientific studies on sea-level rise, a phenomenon where warming temperatures expand the ocean's volume through thermal expansion and the melting of ice sheets. Current projections indicate that the global sea average could rise from 0.2 meter to a high of 2 meters by the end of the century. But effects could be felt long before that -- Strauss said that levels could increase by 8 inches or more by 2050, on top of 8 inches of rise already occurring since 1880. He outlined research last month showing that what are now once-a-century flood events could become one-in-20-year events along the New Jersey shore and annual events in Los Angeles (ClimateWire, March 15). At more than half the 55 sites Strauss studied, storm surges on top of sea rise have "better than even chances" of rising 4 feet above the high tide line by 2030.
$500B in real estate at risk
"Yet nearly 5 million U.S. residents live in 2.6 million homes on land below this level. Multiplied by the national average sales price of existing homes in 2010, this stock comes to more than $500 billion of residential real estate," he said. The challenge for city and state planners is that the scientific projections are so wide, making it difficult to determine what roads need to be raised and which building codes altered in a municipality. In the meantime, there are a lot of things the federal government can do to help local officials, the panel said. Chief among those is ensuring funding for scientific research that illuminates how global models of sea-level rise could play out in a specific location. Federal agencies could provide LiDAR data -- which provide topographical details of the Earth's surface -- to give communities a better sense of which infrastructure is vulnerable, said Freed of New York.
Federal help needed
In another example, the U.S. Geological Survey is working with Broward County, Fla., officials to try and determine the degree that sea-level rise speeds up an underground creep of saltwater toward drinking water supplies. "The U.S. Geological Survey, in coordination with other local agencies, will need to establish a regionwide, formal saltwater intrusion monitoring network," said Berry of Florida Atlantic University.
Additionally, the federal government could help tremendously by changing how it finances certain programs and implements regulations, several panelists said. The most critical action the federal action could take is updating flood insurance rate maps from the Federal Agency Management Agency that have not been revised since 1983, Freed said. The maps inform city and state planning such as building codes. He urged Congress to restore funding for the Department of Housing and Urban Development's Sustainable Communities Program -- which he said helped his city evaluate flood resilience strategies. The program was zeroed out for fiscal 2012, he said. "We cannot do this alone," he said. - AccuWeather.