Scientists have been trying to understand why these events have become more violent, and seemingly more frequent. Their main challenge: they need to understand it as the phenomenon unfolds.
In a matter of weeks, Harvey, José, Irma and Maria hit the Caribbean region with unprecedented violence.
By the way, we have a question for the people who name these natural disasters (the US meteorological office)? Why normal names? Why not Cruella, Voldemort or Donald? End of digression.
This has been a long summer for environmentalists, and for the planet in general. From raging forest fires in Europe to the most intense hurricanes in “many generations” (according to Guadeloupe’s local authorities), the news cycles have been dominated by extreme weather events across the globe.
This catastrophic series does not come as a surprise for the scientific community. The National Hurricane Center (from the USA) had successfully predicted the range and the intensity of the season that was coming then.
Climatology is not the easiest of sciences, but we, the humans, also have a few smart people working on the issue. Here is what they can tell you about hurricanes, their future, and also ours.
1. How do hurricanes form?
A well-known fact thing about climate change: the general temperature of the planet is rising. Fast.
This means that oceans are getting warmer too, which in turn means there is more water vapour in the air. Water vapour is like the fuel of tropical thunderstorms. The hotter it gets, the more this water-heavy air becomes reactive.
Air particles over the surface of the ocean are sucked up all the way up to the high atmosphere (15km high) to transform into rain. This forms cumulonimbus clouds. If the formation doesn’t collapse under its powerful inner rotating winds, then you have the beginning of a storm system.
2. Are there more hurricanes, and are they more powerful?
The frequency and intensity of these events have augmented significantly in the last 30 years. In the last 100 years, 11 of the 33 category 5 hurricanes that have occurred in the Atlantic have happened in the XXIst century. The 2017 season is not the most intense though. 2005 was the real record year, which saw the passing of 26 cyclonic phenomena, including two category 5 hurricanes.
In 2017, there has been 13 storms in the North Atlantic, which is not that unusual. What is weird about this season is that four powerful hurricanes washed over the Caribbean over a particularly short period of time. In recent meteorological history, some of these islands had never experienced powerful hurricanes, as they normally pick up power when they reach the Caribbean sea, beyond the islands. On that year, they’ve had 4 in one season.
Meteorological models predict a 20% rise in the intensity of hurricanes. Intensity, in this instance, means wind power, levels of precipitation, timespan on a given zone and destructive power.
3. Are hurricanes intensifying because of human-induced climate change?
Do carbon particles cause hurricanes? No. Does the indirect warming of the planet, combined with the removal of natural protections lead to greater hurricane risks and greater intensity of these events? Absolutely.
Have human emissions raised the concentration of greenhouse gas in our atmosphere by an astonishing 25% in less than fifty years? Yes. Have natural barriers like forests been replaced by risky urban settlements? In most parts, yes.
A recent multi-agency report on climate change was considered so alarming by its makers that they decided to leak it to the press, for fear of official censorship. It sheds some light on our eventual trajectory:
“Both physics and numerical modelling simulations indicate an increase in tropical cyclone intensity in a warmer world, and the models generally show an increase in the number of very intense tropical cyclones. […] Increases are projected in precipitation rates and intensity. The frequency of the most intense of these storms is projected to increase.”
Leaked US Climate Change report, 2017, published by the New-York Times
Indirectly, the human influence over the environment, and especially the disruption of the temperature regulation mechanism of our planet, does create more favourable conditions for their formation and induces more extreme weather events. That’s more powerful hurricanes, over a longer season and over a larger geographical scope.
4. Is each summer going to be such a drag?
The world is not ending, it’s changing. As it is simpler for a teacher to predict the average score of his class than an individual’s exact result, climatologists can only take this new season into account, and try to make better sense of what we should be doing to lower the incumbent risks. There will be a rise in the average number and strength of extreme weather events.
This summer is what is a globally warmed age. It’s sadly time to stop speaking in the future tense, and start looking at resilience strategies.
If nothing is done, previous gardens of Eden such as the Caribbean rim, or the Pacific Islands, will become uninhabitable or disappear under the repeated assaults of the elements. Humans, animals and plants alike have to adapt to new settings, and new conditions of life.
Climate change is now part of every story. We are now well into the 6th major extinction event of our planet’s History. The previous one was the downfall of dinosaurs, and guess who took over? Mammals, and by extension, us. Can we make sure the bugs don’t take over, at least?