Researchers: Climate change to make Tampa increasingly vulnerable to unprecedented extreme hurricanes
Tampa tends to land on two kinds of lists these days.
The second is the scary hurricane list.
Tampa’s worst-in-the-nation vulnerability to hurricane-driven storm surge made news a year ago and again in June. And it’s been well-documented by University of South Florida researchers Robert H. Weisberg and Lianyuan Zheng.
Now comes yet another grim warning about the bay area’s worst-case scenario. It's not pretty.
The research was published in the scientific journal Nature Climate Change last August by researchers from Princeton University and the Massachusetts Institute of Technology. Last week, it was picked up and expanded upon by Weather Underground founder Jeff Masters, a meteorologist who flew with NOAA’s hurricane hunters in the 1980s.
The bottom line, according to researchers Ning Lin and Kerry Emanuel, is that climate change models predict a rising chance of fierce, highly destructive hurricanes hitting Tampa in the coming century. These could be worse than anything the bay area has ever seen.
Consider the last major hurricane to hit the bay area, in 1921. It drove in a storm surge of 3 meters, or about 9 feet.
Under the climate change-influenced storm models that Lin and Emanuel ran, Tampa could see a hurricane with a storm surge of nearly 6 meters.
“A storm surge of 5 meters is about 17 feet, which would put most of Tampa underwater, even before the sea level rises there,” Emanuel, a professor of atmospheric science at MIT, said in a news release. “Tampa needs to have a good evacuation plan, and I don’t know if they’re really that aware of the risks they actually face.”
Granted, the probabilities would still be very low.
The research showed that an extreme storm — one that couldn’t be predicted from the historical record alone, but might be anticipated once changing environmental factors are taken into account — today could be estimated to drive a 6-meter storm surge into Tampa once every 10,000 years.
As the climate changes, that probability could fall to a chance of a hurricane with a 6-meter storm surge once every 700 years — or 14 times as likely as it is now.
“Summed up over a 30-year time period, a 1-in-700 year event has a 4 percent chance of occurrence — something disaster planners should definitely think about,” Masters said in a lengthy Weather Underground blog post on the Princeton/MIT research, which was partly funded by the National Science Foundation.
“What that really translates to is, you’re going to see an increased frequency of the most extreme events,” Emanuel said. “Whereas the upper limit of hurricane wind speeds today might be 200 mph, 100 years from now it might be 220 mph. That means you’re going to start seeing hurricanes that you’ve never seen before.”
But that, Masters says, does not necessarily mean that hurricanes would be more common generally — just that the most powerful ones could be even more fearsome.
“While an increase in the frequency of hurricanes due to global warming is something many models run by other hurricane scientists do not show happening, there is widespread agreement among hurricane scientists that the strongest storms should get stronger,” he wrote. “Stronger storms are to be expected because hurricanes are heat engines that extract heat energy from the oceans and convert it to wind energy, and any increase in ocean heat energy due to global warming can be expected to increase the maximum potential intensity a hurricane can reach.”
With 2.8 million residents — half of whom live at elevations of less than 10 feet above sea level — the bay area’s life-and-death stakes are high, Masters said.
“Given that only 46 percent of the people in the evacuation zones for a Category 1 hurricane evacuated when an evacuation order was given when 2004's Category 4 Hurricane Charley threatened the region, the potential exists for hundreds or even thousands of people to die when the next major hurricane hits,” he concluded.
He’s not alone. In 2010, the Tampa Bay Regional Planning Council estimated that a major hurricane could cause nearly 2,000 deaths of people who stayed in evacuation areas and mobile homes.
That’s higher than the death toll from Hurricane Katrina in 2005.