Are humans causing stronger hurricanes?
Hurricanes can be a devestating force of nature, as witnessed by the violence of Katrina in 2005. But humans also lend a hand in warming up the waters where hurricanes form, according to a study by the Proceedings of the Nartional Academies of Sciences. Using results from the world's top climate computer models, Tom Wigley of the National Center for Atmospheric Research told Earth & Sky that the observed warming of hurricane-breeding waters "cannot be caused by natural fluctuations, which just leaves human factors as the dominant cause."
DB: I’m Deborah Byrd.
JB: And I’m Joel Block, on the continuing controversy about humanity’s effect on hurricanes. Warm ocean waters fuel hurricanes. And, although not everyone believes it, the evidence indicates that hurricanes have gotten stronger.
DB: In the past couple of years, evidence has been piling up that human activities are helping make hurricanes stronger. For example, a study released on September 11, 2006 ruled out “natural causes” as the primary reason why ocean waters have warmed where hurricanes form over the last 100 years.
Tom Wigley: … the changes cannot be caused by natural fluctuations, which just leaves human factors as the dominant cause.
JB: That’s Tom Wigley, a climate scientist and study co-author. He said those “human factors” include more greenhouse gases into the atmosphere, from burning fossil fuels.
Tom Wigley: The real question is what’s going to happen in the future … I’ll just give you a central estimate. If the warming has been 0.7 of a degree Celsius over the last 100 years, the warming for the next hundred years is probably going to be about four times that much. So that should give people cause for concern about climate change in general and what we can do to slow down the rate of warming.
DB: Do you think human activity can make hurricanes stronger? Tell us what you think at earthsky.org. Our thanks today to NASA. We’re Block and Byrd for Earth & Sky.
Our thanks to:
Tom Wigley
Senior Scientist
National Center for Atmospheric Research
Boulder, Colorado
http://www.cgd.ucar.edu/cas/ACACIA/publications/wigleycv.html
Additional Teacher Resources
NASA: Hurricane Web Page
NASA’s primary hurricane page, this site provides several resources including the latest hurricane news, multimedia resources, and links to more information.
NASA: Climate, Water, and Life – PowerPoint Presentation
This PowerPoint presentation is a useful tool for educators. It provides excellent graphics and text on how our climate is affected by both natural and human impacts.
NASA: Eye to Eye: Seeing Hurricanes as Only NASA Can
Hurricanes are Earth’s most powerful natural phenomena. For years scientists have studied the processes that describe hurricanes. But it’s just recently that the instruments and techniques have been in place to thoroughly analyze and explore the origins of these natural weather engines.
USA Today: New Study Ties Global Warming to Stronger Hurricanes
This article looks at a series of studies that have shown an increase in the power of hurricanes in the Atlantic and Pacific oceans. Storm experts say this is tied to rising sea-surface temperatures. One study indicates that most of the increase in ocean temperature that feeds more intense hurricanes is a result of human-induced global warming.
