With 15 tropical storms, this hurricane season in the waters of the Atlantic breaks several records and causes a lot of alarm, as it confirms that climate change is an imminent reality.
According to specialist sources, 12 tropical storms, of which six reach the potency of a hurricane, are the average weather events occurring during the most turbulent months in the Atlantic Ocean, from 1st June to 30th November.
However, before the beginning of October in 2017, the Caribbean and West Indies region has already been battered by a fortnight of storms, including the six expected hurricanes, of an intensity as unusual as it is devastating.
In this respect, the German climatologist Anders Levermann, explained that global warming associated with climate change will generate increasingly stronger hurricanes, which was demonstrated with the path of the devastating hurricane Irma through the Caribbean and Florida, United States. At its strongest point, that cyclone reached windspeeds of 297 kilometres an hour, more than any other hurricane recorded in the Atlantic Basin in history.
In fact, this weather phenomenon lasted three days as a category 5 hurricane, the highest of all on the Saffir Simpson scale. Its forerunner, Harvey (category 4), produced a record 1.29 metres of rain as it passed over Texas and Louisiana. However, most certainly, why is the worsening impact of hurricanes attributed to climate change?
The main scientific proof is a well-established law of physics: the Clausius-Clapeyron equation, which states that a warmer atmosphere contains more moisture.
On the basis of this premise, for each additional degree, the atmosphere could contain 7% more water, and this tends to make rain events be more extreme when they happen.
Another element that we could mention with some confidence is the temperature of the seas. Hurricanes grow and strengthen in intensity over warmer waters, and, according to international climatological reports, the oceans have warmed up on average between one and three degrees Fahrenheit over the last century.
“These weather phenomenon only form above a sea surface that has a temperature of at least 26.5 degrees Celsius”, explained Bob Ward, the director of politics and communication at the Grantham Research Institute on Climate Change and the Environment in the United Kingdom.
“Average sea surface temperatures have been rising, and some parts of the North Atlantic and Gulf of Mexico are warmer than average at the moment”, added the British expert.
In general, the warmer the sea waters are, the more powerful the storms are, concluded the scientist.
“Hurricanes absorb energy and stay alive thanks to the sea surface temperature, which must be between 26 and 27 degrees Celsius”, he said.
At this point, the specialist added through declarations on the BBC World page, we must take into account the rise of temperatures associated with climate change and emissions of harmful gases into the atmosphere.
Of the surplus heat of the greenhouse effect, only 7% is seen in the surface temperature and the remaining 93% is absorbed by the sea, he indicated.
“If the ocean Surface is warmer, there is more heat to generate very damaging storms and cyclones, but this factor does not imply that the frequency increases every year”, he advised.
Franck Roux, professor of Paul-Sebatier University in France, agreed with this idea. In a study, the expert considered that while global warning could increase the strength of weather events, there is insufficient data to predict whether it will affect its frequency.
In the north Atlantic for two decades there has been a constant rise in the frequency of storms and hurricanes, unlike between 1970 and 1995, said the French meteorologist.
In this region, he added, cyclonic activity follows cycles over several dozens of years and it is still not possible to say if the increase in the number of hurricanes in the region is due to natural variation or climate change.
“The intensity, frequency and duration of hurricanes in the North Atlantic has increased since the beginning of the 80s”, according to the last National Climate Evaluation, a periodic report created by a team of more than 300 scientists and other experts from the United States.
Since 2014 this conglomeration of experts, that the administration of President Donald Trump threatens to dissolve, has confirmed that the frequency of the strongest storms (hurricanes of category 4 and 5) has grown over the last decades. (PL)
(Translated by Donna Davison – Email: firstname.lastname@example.org) – Photos: Pixabay