The two consecutive bleaching events in the past 12 months have left the largest living structure on Earth hanging by the thread, with more than half of its grandeur gone.

Scientists assured that Australia's Great Barrier Reef is not dying. However the back-to-back bleaching event has caused great loss. In their newest survey, researchers from ARC Centre of Excellence for Coral Reef Studies at James Cook University in Queensland found that the center part of the Great Barrier Reef has taken most of the serious blow during this year's bleaching event.

The record-breaking bleaching event last year killed, on average, about 67 percent of the 500-mile coral stretch in the northern section of the reef. Now, with the latest casualties in the central section, the damage of the back-to-back bleaching event has spread another 400 miles.

"That's obviously an enormous loss over two-thirds of the Great Barrier Reef," said Terry Hughes, director of the centre, in a report from Washington Post. "I wouldn't say the barrier reef is dying. But clearly, we're measuring serious losses here. And the reason it's happening is global warming."

In the last 20 years, the Great Barrier Reef has already experienced four major bleaching events: in 1998, 2002, 2016 and 2017. The fastest-growing species of corals may take at least 10 years to make a decent recovery, while slower-growing corals may take far longer.

"Corals are resilient creatures," said Robert Richmond, a coral reef expert and director of the University of Hawaii's Kewalo Marine Laboratory, as per National Geographic. "Given a chance they can come back. We're just not getting any breaks whatsoever, and the severity of the problem is increasing with time."

Unusually warm water temperatures could stress the corals leading to the mass exodus of photosynthetic algae, called zooxanthellae, from their cells. During this time, the corals lose color and turn white; thus, the term "coral bleaching." Corals are more likely to die during longer and stronger bleaching events, just like the ones that occurred last year and earlier this year.