WASHINGTON — Stronger
hurricanes forecast for the next few decades could flood major cities including
Miami and
New
Orleans, environmental scientists
said Wednesday.
Storm surges -- walls of water up to 30 feet high pushed ashore by hurricanes --
could pose a higher risk to coastal areas than the threat of rising seas tied to
global
warming, scientists from the group
Environmental Defense said.
More intense hurricanes -- some as strong as 2005's devastating Katrina -- are
likely in the future, the scientists said, because global
climate
change could mean warmer sea surface
temperatures, which fuel hurricanes' development.
"There's been a lot of talk about the threat to coastal areas of sea level rise,
and that is a very, very real issue ... but one that is going to unfold over a
period of decades, if not a century," said Bill Chameides,
Environmental
Defense's chief scientist, in a
telephone news conference.
"What we think will actually be a more immediate risk to coastal areas ... is
the threat of storm surge, which is actually exacerbated by sea level rise due
to these growing-intensity storms," Chameides said.
Using U.S. government data, the scientists created maps showing flood risk areas
in Wilmington, North Carolina; Charleston,
South
Carolina, and Miami, based on
projections of storm surges from hurricanes ranked as Category Three, Category
Four and Category Five.
FLOOD RISK
A Category Three storm, with a typical surge of 9 feet to 12 feet above normal,
would pose a flood risk to all of Miami Beach and much of downtown Miami,
according to the scientists' projections.
By contrast, a Category Five storm, with surges of 18 feet or higher, would pose
a risk to a larger area, extending further inland, their maps indicated.
The maps and other information are available online at http://www.environmentaldefense.org/go/hurricanes/.
For New Orleans, the scientists did not project possible risk of flooding;
instead, they used data from the U.S.
Geological Survey showing how far the flood waters went after
devastating Hurricane Katrina came ashore last year.
"As Hurricanes Katrina and Rita showed, the 9,546 square miles of land close to
sea level (in Louisiana) are especially vulnerable to storm surges -- highly
destructive moving crests of water that often cause the bulk of the damage in a
high-category storm," the scientists wrote online.
Chameides agrees with many climate scientists who believe human-caused global
warming is responsible for raising sea surface temperatures, making stronger
hurricanes more likely; but other scientists maintain hurricane intensity goes
in natural cycles, and say the record-breaking 2005 Atlantic and Caribbean
season was part of a high-category hurricane cycle.
U.S. government forecasters Tuesday revised their hurricane predictions for
2006, saying the Atlantic hurricane season would be slightly less intense than
last year -- and less active than they predicted in May -- with 12 to 15 named
storms and seven to nine hurricanes, of which three or four could be classified
as "major" hurricanes.
Last year there were 28 tropical storms, of which 15 became hurricanes,
including four major hurricanes, notably Katrina, which devastated New Orleans,
killed 1,300 people and caused $80 billion in damage.