How record-breaking Hurricane Beryl is a sign of a warming world

 

Hurricane Beryl has caused widespread destruction in the Caribbean, highlighting the impact of climate change.

With wind speeds exceeding 160mph (257km/h), it became the earliest recorded category five hurricane in the Atlantic Ocean's history, dating back over a century.

Indeed, the last time a category five hurricane was recorded in July was Hurricane Emily on July 16, 2005.

The reasons behind each storm's occurrence are intricate, making it challenging to directly link specific events to climate change.

However, the unusually high temperatures of the ocean's surface are considered a primary factor in the hurricane's intensity.

Typically, such severe hurricanes emerge later in the year, following the warming of the ocean waters during the summer.

Hurricanes typically require ocean temperatures of at least 27C to form. As illustrated in the map, the waters along Hurricane Beryl's trajectory have been significantly warmer than this threshold.

Assuming all other factors remain constant, rising ocean temperatures lead to more intense hurricanes, as the storms have the ability to absorb additional energy, resulting in greater wind velocities.

"We are aware that as the Earth's temperature increases, so do the temperatures of our oceans," says Andra Garner, a research assistant at Rowan University in the US.

"And we understand that these warm ocean waters serve as a vital source of energy for hurricanes."

In the primary area where hurricanes form in the Atlantic, the amount of heat stored in the ocean – known as ocean heat content – is reaching levels that are uncommon until September.

This is the period when the Atlantic hurricane season is at its peak, as the ocean surface temperatures are typically at their highest at the conclusion of summer.

This concept is demonstrated in the graph below, where each dot signifies a major hurricane that occurred between the years 1940 and 2024. As observed, the majority of major hurricanes occur in late August and September, with occurrences of earlier ones being extremely rare.