Study: Climate change to worsen
hurricane storm surge
Doyle Rice, @usatodayweather, USA TODAY6:49 p.m. EDT March 18, 2013
The USA could see a storm like Hurricane Katrina every two years.
(Photo: Evan Eile, USA TODAY)
STORY HIGHLIGHTS
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Storm surges are projected to increase by as much as 10 times in coming decades
Sea levels will also rise due to global warming
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Storm surge is typically the biggest killer from hurricanes
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Could the USA deal with a Hurricane Katrina every two years?
Such a scenario is possible by the end of the century due to climate change, according to
a study published Monday in the Proceedings of the National Academy of Sciences.
The frequency of extreme storm surges — the deadly and devastating walls of water that
roar ashore during hurricanes — is projected to increase by as much as 10 times in
coming decades because of warming temperatures, the study finds. Global warming has
already doubled the chance of storms like Katrina, according to the study, which was led
by climate scientist Aslak Grinsted of the University of Copenhagen in Denmark.
Storm surge is typically the biggest killer from hurricanes, and also usually causes the
most destruction: Katrina killed more than 1,800 people and caused $125 billion in
damage, mostly from storm surge, while Sandy last year killed dozens and caused at
least $50 billion in damages.
Grinsted's research shows that there will be a tenfold increase in frequency of storm
surges if the climate becomes 3.6 degrees Fahrenheit warmer. "This means that there
will be a 'Katrina' magnitude storm surge every other year," he says.
One estimate from the Intergovernmental Panel on Climate Change shows that, under
one of the "best-case" scenarios, Earth's atmosphere's temperature will rise anywhere
from 2.0 to 5.2 degrees by the end of the century.
Grinsted says that a 0.7 degrees warming of the climate "corresponds to a doubling of
the frequency of extreme storm surges like the one during Hurricane Katrina. With the
global warming we have had during the 20th century, we have already crossed the
threshold where more than half of all 'Katrinas' are due to global warming," he says.
This research used past storm surge data from six tidal gauges from the East and Gulf
Coasts, all of which had information dating to the 1920s. The study also used this gauge
data to look forward to the likelihood of future storm surges.
In addition to there being more extreme storm surges, the sea will also rise due to global
warming, Grinsted says. As a result, the storm surges will become worse and potentially
more destructive.
However, another expert finds fault with the study: "I find this paper to be very
misleading," says Georgia Tech climatologist Judith Curry, who says they used "a very
incomplete data set:" It only considers tide gauge measurements at six locations (Atlantic
City, Charleston S.C., Mayport, Fla.; Pensacola, Fla.; Key West, and Galveston, Texas.)
"Their statistical projection is totally unconvincing, since it is based on a data set that
incompletely represents U.S. landfalling hurricane activity since 1923," Curry says. Their
data set is much inferior to other data sets, she says, such as the standard hurricane
landfall data set maintained by the National Hurricane Center.
And while Curry admits that "it is likely that the maximum intensity of the strongest
hurricanes would increase in a warmer climate, I do not currently place much confidence
in climate model projections of future hurricane activity."