P!N-Q&A: Will Global Warming Turn up the Heat on Hurricanes?

P!N-Q&A: Will Global Warming Turn up the Heat on Hurricanes?
Will Halicks answers burning questions about the relationship between climate change and severe storms

With winter at the door and leftovers still cluttering the fridge, it might seem like an odd time to be thinking about global warming. But the end of hurricane season doesn’t mean bad weather is taking a vacation.

In fact, a recent study suggests that hurricane season in the north Atlantic might be getting longer. The current season runs from May to November. But as climate change brings longer periods of warm weather, the number – and ferocity – of storms could be growing.

Opinions vary among experts, and the heated debate over the link between climate change and storm severity shows little signs of cooling off. Below, PLAN!T NOW answers your questions about what global warming might mean for hurricanes.

Q: Should we be worried about more severe storms?

Maybe.

Dr. Mojib Latif, a professor of ocean dynamics at the University of Kiel in Germany, says it’s too soon to tell. Hurricane activity fluctuates greatly over time – the 1950s saw a spike in the number and strength of hurricanes that tapered off as quickly as it had come. Latif says it would be inaccurate to point to recent peaks in hurricane activity, even the ferocious 2005 season that included Katrina, as signs that something is changing.
“I think it is premature at this point to say that there is a discernible influence of global warming happening on hurricane statistics,” he says.

The Union of Concerned Scientists in Massachusetts reports differently. In a study published several months ago, the organization said the threat from climate change is real and immediate.

“With all other factors being equal, experts expect higher ocean temperatures to strengthen hurricanes, which can strike almost anywhere in the Southeast and Gulf Coast region, taking lives and causing enormous damage,” the study says.

Q: What kind of damage?

Flooding, for a start. Under the study’s high-emissions scenario, half of Florida’s existing beaches and almost all of its mangrove swamps into the zone most vulnerable to year-round flooding by 2060. Hurricane-related deaths in Florida each year could rise to 37, up from an average of eight annually.

The study says the annual costs of hurricanes under the high-emissions scenario could total more than $111 billion – that’s if our production of greenhouse gases continues to accelerate.

Q: What about a longer hurricane season?

Jeff Tapp, an associate professor at the University of Purdue, says the number of days in a year that favor severe storms could as much as double in places like New York in Atlanta.

“What we found is that increases in human-induced greenhouse gases will lead to more frequent severe storms in the United States,” he says. “This obviously impacts people in terms of hazards to their life and property.”

Q: Has climate change affected the landscape of storm zones in the Atlantic?

Latif, of the University of Kiel, says he has noted one major change: a storm in the southern Atlantic ocean, the only tropical ocean in the world that doesn’t experience severe storms.

“This is due to the upwelling of cold waters from deeper ocean levels,” Latif says. “This keeps the south Atlantic cold, and therefore we don’t experience hurricanes in this area.”

However, in 2006, a storm did appear in that region. And early this year, a subtropical cyclone hit the area as well. Although weaker than the 2006 storm, this year’s cyclone caused 14 deaths in South America and forced thousands of people to evacuate. A state of emergency was declared in four cities.

That was in January, well outside the current hurricane season.

“This may be a region which will favor hurricanes, in contrast to the last decades or centuries,” Latif says.

The studies and interviews referenced in this article are all available online:

Climate Change in the United States: The Prohibitive Costs of Inaction
© August 2009, The Union of Concerned Scientist
http://www.ucsusa.org/assets/documents/global_warming/climate-costs-of-inaction.pdf

Warmer temperatures could increase storm severity, expert says
© August 2009, Deutsche Welle
http://www.dw-world.de/dw/article/0,,4598235,00.html

Global Warming Increasing Storm Severity
© redOrbit
http://www.redorbit.com/news/video/science/5/global_warming_increasing_storm_severity/26818/index.html