Do we need a category six in defining storms? Some climate scientists think so, as tropical cyclones increase in duration, intensity, and strength. Climatologist Michael Mann told The Guardian, “Scientifically, [six] would be a better description of the strength of 200 miles per hour storms, and it would also better communicate the well-established finding now that climate change is making the strongest storms even stronger.”
The Saffir-Simpson Hurricane Wind Scale currently runs from one to five, based on sustained wind speed, according to the National Hurricane Center. Should we change the scale to include a six rating? Climate scientists at the Pacific Climate Change Conference in Wellington, New Zealand floated the idea, according to The Guardian.
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New Zealand climate change minister James Shaw said 2016’s Cyclone Winston could have been a category six storm if that rating existed. Winston, according to The Guardian, is the strongest cyclone we’ve recorded in the Southern Hemisphere. Shaw said at the conference, “The only reason it wasn’t a category six cyclone is because we don’t have a category six, but we might need one in the future.”
Mann said adding category six or reevaluating the scale could hold implications for how communities prepare for cyclones, and for how scientists understand changing cyclone behavior in the climate change era.
But not everyone is convinced we need a category six. Principal scientist Chris Brandolino at New Zealand’s National Institute of Water and Atmospheric Research said meteorologists and the public are already familiar with the established scale, saying, “Categories are engaging to the public and it’s easy for us to understand and communicate the severity of a storm. I always encourage us reevaluating the science, we should always be asking, ‘Is what we are doing appropriate for the time?’ But I think if we are seriously to consider this it requires a holistic approach, looking at the whole scale, not just adding a category. Maybe the whole scale gets rejigged to reflect the times.”
Via The Guardian