Climate warming has dealt yet another blow to the Great Barrier Reef

Australia’s Great Barrier Reef is experiencing its sixth massive bleaching event as climate change has warmed the ocean, raising concerns over whether one of the world’s natural wonders is nearing a tipping point.

Reef managers confirmed Friday that aerial surveys detected catastrophic bleaching on 60% of the reef’s corals.

It is the sixth massive bleaching the reef has suffered in two decades, and the fourth since 2016. Back-to-back bleaching events in 2016 and 2017 affected two-thirds of the world’s largest reef.

“The pace at which bleaching events are now occurring on the Reef is a matter of huge concern,” Australia’s Great Barrier Reef Foundation said in a statement.

“It is too early to know the level of long-term damage that the bleaching has caused,” the foundation added, “because many corals will recover once thermal stress declines. However, based on what’s happened in the last five years, we would expect to see severe coral mortality in the shallowest regions of the worst affected reefs.”

Two years ago, researchers who analyzed the health of reef’s coral populations since 1995 concluded that warming has killed off half of them — and that these colonies may never recover.

John “Charlie” Veron, a renowned expert who has dived the Great Barrier Reef for 45 years and is known as “The Godfather of Coral,” is now predicting their extinction.

“It’s the beginning of a planetary catastrophe,” Veron told CNN. “I was too slow to become vocal about it.”