Scientists propose a Category 6 as hurricanes gain in intensity with climate change
A pair of climate scientists are proposing a sixth category for hurricanes as climate change increasingly intensifies these storms, according to a new research study.
In a study, published Monday in the Proceedings of the National Academy of Sciences, the two scientists argued the "open-ended" Saffir Simpson hurricane wind scale is becoming increasingly "inadequate" as the globe continues to warm.
The scale, developed in the early 1970s, may not reflect the true intensity of some storms, argued study co-authors Michael F. Wehner — a climate scientist at the Lawrence Berkeley National Lab — and James P. Kossin — a former NOAA climate and hurricane researcher.
A Category 6 designation would apply to storms with winds that exceed 192 miles per hour under their proposal.
Storms with winds of 157 mph or higher are currently ranked Category 5, an open-ended approach that fails to adequately warn people of the dangers of higher wind speeds, the study contended.
The study's co-authors believe the open-ended nature of the current scale will prompt people to underestimate the risk of some hurricanes, which will become "increasingly problematic in a warming world."
"We find that a number of recent storms have already achieved this hypothetical category 6 intensity and based on multiple independent lines of evidence examining the highest simulated and potential peak wind speeds, more such storms are projected as the climate continues to warm," the study stated.
Since 2013, five — all in the Pacific — reached wind speeds of 192 mph or higher, with warming conditions expected to bring even stronger weather, The Associated Press (AP) reported.
“Climate change is making the worst storms worse,” Wehner told the news wire.
Some experts told The AP they do not believe another category is needed, and could give people the wrong impression as it's based on wind speed, rather than water — the deadliest element of hurricanes.
University of Miami hurricane researcher Brian McNoldy reportedly noted climate change is not causing more storms, but rather intensifying storms and increasing the proportion that qualify as major hurricanes. This is driven by warmer oceans, McNoldy said.
Kossin told The AP pacific storms are stronger as there is less land to weaken them, in contrast to the Gulf of Mexico and Caribbean. While no Atlantic storm has reached the 192 mph threshold, Kossin and Wehner told the news wire the world warming will create a greater chance in the future.
Jamie Rhome, deputy director of the National Hurricane Center, noted to the news wire that his office attempts “to steer the focus toward the individual hazards, which include storm surge, wind, rainfall, tornadoes and rip currents, instead of the particular category of the storm, which only provides information about the hazard from wind."
Rhome added a Category 5 already suggests "catastrophic damage" from wind so adding a higher category would not be necessary even in the case storms get stronger, the AP noted.