ian is no longer a hurricane. As the storm swept across Florida on Thursday morning, US time, the US National Hurricane Center downgraded it to a tropical storm. as ian on Wednesday near Fort Lauderdale in southwest Florida, he did so with wind speeds of around 240 kilometers per hour, as a hurricane of level 4 of 5. That is already in the absolute top field, only four hurricanes have been stronger than them met ashore in Florida.
The five categories of hurricanes however, relate solely to the maximum wind speeds and not to the risk of storm surges and heavy rain. ian pushes a lot of water into the coastal areas, in some places a rise in sea level by more than five meters was predicted. And also as a tropical storm, with speeds of around 100 kilometers per hour ian still carries a lot of water with it, so even inland it could cause flooding.
Some are now wondering what role climate change plays in the development of ian has played. “We already know it’s stronger and putting down a lot more rain than the same hurricane would have done a hundred years ago,” tweeted Texas Tech University climate scientist Katharine Hayhoe. The question is not whether climate change caused a particular hurricane, but how much worse global warming has made it. And a spokesman for UN Secretary-General António Guterres said the hurricane was “another example of dramatic climate activity that we are seeing around the world with increasing frequency and increasing destruction.”
There will not necessarily be more hurricanes – but they will become more destructive
is secured according to NASAthat the average number of North Atlantic hurricanes has increased since the 1980s. Not only are there more and more storms in a hurricane season, they have also become stronger. However, the development is still largely within natural climate fluctuations. Especially since the period under consideration for rather rare events such as hurricanes is quite short: since the late 19th century, so a study from last year, major hurricanes in the Atlantic have not become much more frequent. However, another study published in 2019 found in the specialist magazine Naturethat the genesis of hurricanes in the Atlantic has changed between 1982 and 2009: An unusually large number of hurricanes are now growing very quickly into very intense hurricanes. The team also interprets this acceleration as a result of climate change. If the earth warms up by two degrees, the maximum wind speeds of hurricanes are likely to increase by one to ten percent in the long term, according to the latest assessment report from the Intergovernmental Panel on Climate Change.
However, it’s not just about wind speeds. Rising sea levels also cause storm surges to rise higher as tropical storms make landfall. This means that larger areas will be flooded than before. In addition, warmer air can absorb more water. As the earth continues to warm, hurricanes are likely to bring more precipitation with them. Researchers have already demonstrated such changes in precipitation patterns on the coasts of Japan, South Korea, Taiwan and southeastern China. Typhoons, as tropical storms are called in the Pacific, have been bringing heavy rain there since 1986, according to a study in the journal Nature communication. This increase cannot be explained solely by natural fluctuations.