Typhoon Haiyan, which made landfall in the Philippines on Nov. 7, is another sobering reminder of the severe weather we are provoking through climate change. It is unofficially the strongest recorded cyclone to ever make landfall, with wind speeds up to 195 mph, 70% stronger than Hurricane Sandy. Villages are flattened, and more than 5,000 people are confirmed dead (as of 11/22). Greg Laden says that tropical cyclones feed on heat energy from the sea’s surface, from seas we know are getting warmer. Haiyan was a storm that blew past the most dire classification, Category 5, which tops out at a sustained wind speed of about 155 mph. But Greg says the Saffir-Simpson scale is not really about wind speed, it’s about destructiveness, and sustained 155 mph winds are all you need for total destruction. So would it be a good idea to extend the scale to Category 6 or 7 for storms like Haiyan, or will this lead the public to feel that a Category 5 storm is less of a threat? Greg says we should focus less on the numbers and more on educating people on the dangers of cyclones, whose destructiveness will vary not only with wind speed but also with regional topology, the quality of infrastructure, and other local variables. Coby Beck on A Few Things Ill-Considered says “In addition to destructive winds, hurricanes bring storm surges and tremendous rainfall, both of which can pack a worse destructive punch than the direct effects of wind.” Coby suggests modifying the Saffir-Simpson scale with categories like 5B and 5C, which would reflect the increasing strength of storms like Haiyan without “diluting the ‘run for your life’ message category 5 is supposed to deliver.”
Posted to the homepage on November 11, 2013.