Are hurricanes becoming more powerful?
Image from NOAA's GOES satellite. September 14, 1999. Produced by Hal Pierce, Laboratory for Atmospheres, NASA Goddard Space Flight Center. See an animation of how hurricanes form.
DB: This is Earth and Sky. A hurricane gets its power from heat that’s transferred into the atmosphere from evaporating seawater.
JB: So as ocean temperatures increase, so does the potential power of hurricanes. That’s one reason so many climate models predict that hurricanes will get worse, as Earth’s climate warms.
DB: Some scientists say it’s too soon to see these effects. But Kerry Emanuel at the Massachusetts Institute of Technology analyzed hurricane measurements made by aircraft and satellites from around the world. He found an upswing in hurricane intensity, especially since the mid-1970s. So the number of hurricanes isn’t changing.
Kerry Emanuel: What is changing, is the total amount of energy consumed by hurricanes over the course of their life… more of the storms are reaching higher intensities as measured by wind speeds, or as measured by their categories. But on top of that, they’re lasting longer… they tend to maintain high intensity for longer than they used to.
JB: There’s a natural 20- to 40-year cycles of hurricane intensity, he says. But only 12% of storms happen in the Atlantic.
Kerry Emanuel: When people say it’s dominated by 20- to 40-year cycles, they’re talking about the Atlantic. I’m talking about the world.
_DB: For a full transcript of our interview with Kerry Emanuel, come to earthsky.org. Special thanks today to NASA explore, discover, understand. We’re Block and Byrd for Earth and Sky.
Read Earth and Sky’s interview with Kerry Emanuel.
Read Kerry Emanuel’s article in Nature.
Animation showing how hurricanes form.
Learn about hurricanes from Earth’s distant past.
Determining which storms turn into hurricanes.
Using computer models to predict hurricane strength in a warming climate.
Visit the National Hurricane Center.
Our thanks to:
Kerry A. Emanuel
Professor of Meteorology
Massachusetts Institute of Technology
Cambridge, MA
Additional Teacher Resources
NASA: Eye to Eye: Seeing Hurricanes as Only NASA Can
Not lightning. Not tornadoes. Not volcanoes, nor even earthquakes. By a wide margin, hurricanes are Earth’s most powerful natural phenomena. For years scientists have studied the processes that describe hurricanes. But it’s only just recently that the instruments and techniques have been in place to thoroughly analyze and explore the origins of these natural weather engines.
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.
