Hurricane Beryl is ravaging parts of the Caribbean – and putting the spotlight on the role of climate change.
With maximum sustained winds of more than 160 mph (257 km/h), it became the earliest Atlantic Category 5 hurricane in the 100-year-old record.
In fact, only one Category 5 Atlantic hurricane occurred in July – Hurricane Emily on July 16, 2005.
The causes of individual storms are complex, making it difficult to fully attribute specific occurrences to climate change.
- author, Mark Poynting
- role, Climate Reporter
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But exceptionally high sea surface temperatures are seen as the main reason why Hurricane Beryl was so powerful.
Usually, such strong storms develop only later in the season, after the seas have warmed during the summer.
Hurricanes generally need a sea surface of at least 27C to have a chance of developing. As the map below shows, the waters in Hurricane Beryl’s path were much warmer than this.
All things being equal, warmer seas mean stronger storms because storms can absorb more energy, resulting in higher wind speeds.
“We know that as we warm the planet, we also increase the temperature of our sea surface,” explains Andra Garner, an assistant professor at Rowan University in the US.
We know that warm ocean waters are a critical source of fuel for hurricanes.
In the main Atlantic storm development region, the ocean’s heat content—the energy stored in the water column—is at a level not normally seen until September.
That’s when the Atlantic hurricane season is usually most active because the sea surface is usually warmest in late summer.
This is illustrated in the chart below, where a dot represents a major hurricane between 1940 and 2024. As you can see, the biggest storms occur in late August and September, and early storms are very rare.
The number of hurricanes is not increasing, but a higher proportion of them are likely to reach the top global categories as temperatures rise.
“Although it is not known to what extent climate change contributed to the early formation of Hurricane Beryl, our climate models suggest that the average intensity of hurricanes will increase in the future due to increased global warming,” explains Hiroyuki Murakami, Noaa’s Geophysical Researcher. Laboratory of Fluid Dynamics.
Another factor to consider this year is regional weather patterns.
El Nino inhibits the formation of strong storms in the Atlantic because it affects the winds in the atmosphere. The opposite phase, known as La Niña, favors the development of Atlantic hurricanes.
Currently there are “neutral” conditions – neither El Nino nor La Nina. But La Niña conditions are expected later this year.
This likely shift – as well as rising sea temperatures in July and August – has led to concerns that stronger storms could form later in the season.
“Hurricane Beryl sets the precedent for what we fear will be a very, very active, very dangerous hurricane season that will affect the entire Atlantic basin,” said Co Barrett, deputy secretary-general of the World Meteorological Organization.
rapid reinforcement
Meteorologists and climate scientists also noted how quickly Hurricane Beryl strengthened.
It took just 42 hours to go from a tropical depression — with maximum sustained winds of 38 mph or less — to a major hurricane (meaning greater than 111 mph).
“What makes Beryl special is that […] has strengthened the fastest from a tropical depression to a hurricane [of any Atlantic hurricane in June or early July]”- explains Shui Chen, a professor of atmospheric science at the University of Washington.
Hurricane Beryl is an example of “rapid intensification” – where the maximum wind speed increases very quickly. This can be especially dangerous because communities have less time to prepare.
“Unprecedented as beryl is, it’s actually very consistent with the extremes we expect in warm climates,” says Dr. Garner.
“As we warm the planet, we are essentially setting ourselves up for extreme events, making Hurricane Beryl not only possible, but more likely.
“It’s up to us to reduce our emissions to change this story.”
Graphics by Ervan Rivo
