Does the hurricane scale need a Category 6? New climate study found 5 recent storms have met the threshold.

As global temperatures continue to increase, making storms more intense, some researchers say that the Saffir-Simpson scale, which measures a hurricane's wind speeds, doesn't adequately address the hazards associated with extreme storms. In a new study, scientists explored a hypothetical expansion of the scale to include a Category 6, and found that such a designation could help focus people of the worsening risks. 

In a new study, published Monday in Proceedings of the National Academy of Sciences, researchers found that the scale, which was created in the early 1970s and is still used to define hurricane categories, has a "weakness": tops out at Category 5 even though "the destructive potential of the wind increases exponentially."

The hurricane categories run from 1 to 5, with Category 5 hurricanes having wind speeds of 156 mph or stronger — enough to produce "catastrophic" damage, which NOAA says can result in "complete roof failure on many residences and industrial buildings," as well as extended power outages.