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NOVA scienceNOW: Stronger Hurricanes

Program Overview

Scientists examine the relationship between the increase in sea surface temperature and the increase in the number of strong (category 4 and 5) hurricanes. Because hurricane cycles can span two to four decades, scientists explain that there is evidence, but not yet enough data to prove, that global warming causes these increases.

This NOVA scienceNOW segment:

  • explains that though the number of hurricanes year to year is relatively consistent, 2005 was a record-breaking hurricane season in terms of the number of powerful hurricanes.

  • states that hurricane intensity is influenced by sea surface temperature, wind currents, and atmospheric moisture levels, and that storms tend to be stronger when the oceans are warmer.

  • explores whether global warming may be contributing to the intensity of hurricanes, because the number of powerful hurricanes has doubled in the past 30 years.

  • mentions that global ocean temperatures increased 0.5°C between 1970 and 2005—an enormous change. The speed of this increase suggests that the warming is due to human actions.

  • reports that multiple pieces of evidence correlate the increase in storm intensity with the recent increase in sea surface temperature.

Taping Rights: Can be used up to one year after the program is taped off the air.

Teacher's Guide
NOVA scienceNOW: Stronger Hurricanes