For more realistic risk prevention, a team of American researchers supports the need to add a new category to the Saffir-Simpson scale, the official measurement tool for assessing the intensity of tropical cyclones.
With the amplification of cyclones caused by climate change, these extreme weather events can reach wind speeds in excess of 309 km/h.
Each climatic event has its own scale: Richter to assess the amplitude of earthquakes, Imamura to measure that of tsunamis… or the Saffir-Simpson scale for cyclones, hurricanes and typhoons. Problem: the latter is becoming too weak to gauge wind speeds and the risks of these extreme storms, on a planet increasingly subject to climate change.
Question of amplitude
This is the conclusion of a team of American researchers from the Massachusetts Institute of Technology, who published a report in the journal PNASin which she suggests the creation of a new category to identify tropical cyclones of unprecedented magnitude.
“We are investigating the possibility of extending the Saffir-Simpson scale to a sixth category to indicate that climate change has led to a significant increase in the winds of the most intense tropical cyclones,” the researchers said.
The study recalls that the Saffir-Simpson scale was created in the 1970s to classify damage according to the wind intensity of tropical cyclones. It is currently limited to category 5, with a maximum risk level set at a wind speed equal to or greater than 252 km/h (70 m/s), which means that the level of danger remains the same, even if its power goes beyond this measurement.
“This can be considered a weakness of scale, especially considering that the destructive potential of wind increases exponentially,” the research points out.
Towards a new category?
With this in mind, the authors of this study suggest creating category 6, when the wind speed of cyclones exceeds 309 km/h (85m/s). Estimates based on data indicating that of the 197 tropical cyclones classified as Category 5 between 1980 and 2021,Five of them would fall into hypothetical category 6.
These extreme storms all produced in the last nine years, and most in the Western Pacific. “Based on several independent data sources examining simulated and potential maximum wind speeds, we expect more such storms as the climate continues to warm,” the researchers conclude.