Survivors of 2017’s Hurricane Irma, as well as numerous scientists who follow hurricanes, are calling for the addition of a new Category 6 designation to the Saffir-Simpson scale that currently goes to category 5, or storms with winds of 157mph or more.
They say evidence shows that climate change is causing stronger hurricanes, and they cite Hurricane Irma as having the strongest wind speeds ever recorded in the open Atlantic. The National Center for Atmospheric Research believes that with rising global temperatures, hurricanes can move more slowly, have higher wind speeds, and drop more rain.
Tom Krall, who survived Irma in the U.S. Virgin Islands, adds, “It feels kind of like if you’re driving in a car at 75 and you stick your head out the window. You’ve got that kind of an uncomfortable thing in your ears. Once you get up around 185, 200, the roar is like you’re inside a 747 jet engine. It’s extremely intense. You feel it in your gut.”
Mike Mann, an atmospheric science professor at Penn State University, says, “We are seeing a qualitatively different type of hurricane now posing a threat to us and our infrastructure.”
However, researchers at the National Hurricane Center in Miami say the category 6 designation is not necessary, because water rather than wind causes most deaths in hurricanes.
According to Chris Davis, a senior scientist with the National Center for Atmospheric Research, “It is the storm surge, the rainfall, combination of inundation from waves and surge that really kills the most people and does the most damage.”
Penn State’s Mann adds, “Frankly, a 200 mph monster like Patricia, or a 185 mph monster like Irma for that matter, poses a far greater threat than a marginal 157 mph Cat 5 storm.” Hurricane Patricia, which formed in October 2015 and affected Central America, Mexico, and Texas, was the second-most intense tropical cyclone ever recorded worldwide.