Maryland urged to plan for 2-foot sea-level rise by 2050

Saying climate change is already underway, a panel of scientists is urging Maryland officials to plan to accommodate rising seas of up to 2 feet along the state's shoreline in the next 40 years — and perhaps nearly 6 feet by the end of the century.

In a report to be released Wednesday and commissioned by Gov. Martin O'Malley, the group of 21 scientists from Maryland, Virginia and other mid-Atlantic states said recent, more sophisticated studies suggest that sea level is rising faster than forecast just five years ago.

With 3,100 miles of bay and ocean coastline, Maryland is vulnerable to a rising sea level, experts say. The state has 450 facilities and about 400 miles of roads and highways in low-lying areas that could experience flooding aggravated by climate change, according to state officials.

In the wake of Superstorm Sandy's devastating floods last year along New Jersey and New York's coast, O'Malley asked for an update of sea-level rise projections in Maryland to help state agencies decide where and how to construct state buildings, especially in low-lying coastal areas. He issued an executive order in December directing that all new and rebuilt facilities be planned and constructed to avoid or minimize flood damage.

"It doesn't need a lot of rocket science," said Donald Boesch, president of the University of Maryland Center for Environmental Science, who chaired the group's deliberations. "We've got tide gauges that show us sea level is increasing. This is a real phenomenon. We should take it seriously and have to plan for it."

The report comes on the heels of President Barack Obama's speech Tuesday in Washington outlining steps he plans to take with or without Congress' help to fight climate change and to assist communities nationwide in adapting to its impact, including droughts, wildfires and flooding.

O'Malley, still in Ireland after finishing a trade mission there, said in a statement that the state is "committed to taking the necessary actions to adapt to the rising sea and guard against the impacts of extreme storms." He said he wanted the latest scientific advice so that officials can decide "how best to protect our land, infrastructure and most importantly, the citizens of Maryland."

O'Malley's environmental policies have rankled some state Republicans, who see added regulation as burdensome and unnecessary.

"For an Administration that's grown spending and raised taxes at record levels, it is unwise to direct precious taxpayer dollars to yet more expensive projects that promote Governor O'Malley's national political ambitions, not what is in the best interests of Marylands' citizens," Del. Nicholaus Kipke, House GOP leader from Anne Arundel County.

State officials have been urging leaders of Maryland's coastal counties and communities to adjust their building codes and zoning to take sea-level rise into account. O'Malley already has directed the state Department of General Services to update its design guidelines so that any new or rebuilt state structures will be elevated at least 2 feet above where planners project floodwaters could reach once a century.

The report acknowledges that Chesapeake Bay and ocean waters may rise by only about a foot by 2050, but its authors said worst-case planning for a 2-foot rise in waters is warranted to account for the risks of storm-driven flooding.

Boesch said the panel reviewed studies and computer modeling done since a 2008 report assessing potential climate change impacts in Maryland, which had projected that sea level could rise 2.7 feet by the end of the century. More recent research points to more rapid increases, he said, including findings that polar ice is melting more quickly than previously thought and that sea level is rising faster along the mid-Atlantic coast because of a slowdown in the Gulf Stream.

Sea level has risen by roughly a foot in Maryland over the past century, with half of that coming from a gradual, natural sinking of the land, and half from encroaching seas as warming ocean water expands.

The scientists said their best estimate for sea-level rise by 2050 is 1.4 feet, but that it's unlikely to be more than 2.1 feet or less than 0.9 feet. They said it's mostly likely to rise 3.7 feet by 2100, but could range from 2.1 feet to 5.7 feet.

"There's a lot we don't know … about what's going to happen at the end of the century,'' Boesch said, especially given uncertainty over whether the United States and other nations will alter their emissions of carbon dioxide and other greenhouse gases in coming years. "But frankly, there's not a lot we can do now in terms of reducing our emissions … by 2050."

U.S. carbon pollution fell last year to its lowest level in two decades, Obama said Tuesday. But with carbon dioxide levels in the atmosphere reaching unprecedented levels this year, many climate scientists say some warming from the buildup of greenhouse gases is underway and that emission reductions are needed to forestall a more severe impact.

Meanwhile, the state is helping the Federal Emergency Management Administration update flood insurance rate maps for Maryland's 16 coastal counties, the first revision in 25 to 30 years, said David Guignet, who is coordinating the effort for the state Department of the Environment.

With insurance rates expected to jump substantially to cover damage claims from Sandy, Hurricane Katrina and other tropical storms, Guignet said, state officials are urging coastal communities to act now to offset those increases by adopting requirements that new or rebuilt homes or other structures be elevated similar to those facilities under the state's rules.

Most communities still are reviewing the new maps, he said, but more than half of those that have finished have adopted or maintained such rules. Crisfield, for example, which suffered major flooding during Sandy, will be requiring a minimum 2-foot elevation for new or improved homes and buildings in flood-prone areas.

In some particularly vulnerable areas, Boesch said, it may take more to flood-proof a building or protect water, sewer and other public facilities from encroaching waters.

"We have to decide whether the infrastructure is going to be maintained, or have assistance programs to relocate,'' he said. "We already have roads that are periodically underwater, so at some point, what do you do? Elevate the roads, allow increased flooding or abandon?"

tim.wheeler@baltsun.com