By 2100, Baltimore's Harborplace could be under water at high tide. Ocean City might be frequently evacuated because of Atlantic storms. Hooper and Smith islands in the Chesapeake Bay could join 13 others that have been submerged in the estuary.
Across Maryland, almost 1,000 square miles of coastal land are threatened by rising sea levels, scientists warn.
These are a few of the local effects of global warming that researchers are discussing in the wake of a new report by a United Nations panel. More than 2,500 scientists from 130 countries in the Intergovernmental Panel on Climate Change predict that sea levels will rise by up to two feet over the next century.
This figure is lower than a 2001 estimate of as much as a three-foot rise.
But scientists in the Chesapeake region took little comfort in that, in part because land in this area is also sinking at a rate of about seven inches a century - making it a particularly vulnerable area.
Donald F. Boesch, president of the University of Maryland Center for Environmental Science, said the most recent U.N. summary of the state of scientific consensus probably underestimates the rate of sea level rise. He said it doesn't take into account more studies over the past few months that suggest that the Greenland ice sheet and parts of Antarctica might be melting faster than previously thought.
"It's not reassuring," Boesch said. "If I were a prudent person, I would plan for a 2- to 4-foot rise in sea levels in the Chesapeake Bay. But be prepared for the possibility of much more shocking rates of polar ice melt, which could raise sea levels by five or even six feet this century."
The damage caused by rising water levels is magnified during storms, when winds drive surges of water up the Chesapeake Bay and other waterways. Tropical Storm Isabel in 2003, for example, drove a seven-foot storm surge into downtown Baltimore, flooding the Harborplace retail complex and nearby blocks.
That kind of flooding could become common at the busy corner of Pratt and Light streets - not just during storms but several times a year during normal high tides, Boesch said.
"There are several options, and one is to build sea walls," Boesch said. "The other alternative is to retreat to higher ground."
The scientific panel predicts in its most recent report that global sea levels will rise by seven inches to 23 inches by 2100. Average global temperatures could climb by up to 8 degrees over that time.
