In recent years, scientists have debated whether human-caused global warming is affecting hurricanes by making them stronger or causing them to occur more frequently. (Related: "Rising Temperatures May Cause More Katrinas.")
In theory, warmer atmospheric temperatures should lead to warmer sea surface temperatures, which should in turn support stronger hurricanes.
The number of Category 4 and 5 hurricanes worldwide nearly doubled from the early 1970s to the early 2000s. Moreover, both the duration of tropical cyclones and their strongest wind speeds have increased by about 50 percent over the past 50 years.