Hurricanes have become so powerful due to the climate crisis that there is a need to expand the classification to include a “category 6” storm, extending the scale from the standard 1 to 5, as per a recent study. In the past decade, it was found that five storms would have been categorized as this new category 6 strength, including all hurricanes with sustained winds of 192mph or more. These mega-hurricanes are increasingly likely due to global heating, with studies indicating the warming of the oceans and atmosphere. Michael Wehner, a scientist at the Lawrence Berkeley National Laboratory in the US, stated that “192mph is probably faster than most Ferraris, it’s hard to even imagine”. He, along with another researcher, James Kossin of the University of Wisconsin-Madison, has proposed the new category 6. The study, published in Proceedings of the National Academy of Sciences, suggests an extension to the widely used Saffir-Simpson hurricane scale, developed in the early 1970s by Herbert Saffir, a civil engineer, and Robert Simpson, a meteorologist who was the director of the US National Hurricane Center. This scale classifies any hurricane with a sustained maximum wind speed of 74mph or more to be a category 1 event, with the scale rising in line with the speed of the winds. Category 3 and above is considered to include major hurricanes that endanger significant damage to property and life, with the strongest, category 5, including all storms that reach 157mph or more. The new study argues there is now a class of even more extreme storms that demands its own category, including Typhoon Haiyan, which led to over 6,000 casualties in the Philippines in 2013, and Hurricane Patricia, which reached a top speed of 215mph when it formed near Mexico in 2015. While the total number of hurricanes is not increasing due to the climate crisis, researchers have found that the intensity of major storms has notably increased during the four-decade satellite record of hurricanes. A super-heated ocean is providing additional energy to rapidly intensify hurricanes, aided by a warmer, moisture-laden atmosphere. Wehner said the Saffir-Simpson scale was an imperfect measure of the dangers posed to people by a hurricane, with the risks primarily coming from severe rainfall and coastal flooding rather than the strong winds themselves, but a category 6 would highlight the heightened risks brought by the climate crisis. The systems used to chart the world around us have been adjusted to reflect the rapid changes of the modern era. Australia’s bureau of meteorology included a new color – purple – to its weather maps to account for intense heat, while the US government’s Coral Reef Watch program added three new alert categories to capture the increasing heat stress suffered by corals. There is currently no indication that hurricanes will soon be officially classified as category 6, however. The US National Hurricane Center did not respond to a request for comment about the new study.
