Scientists warn Great Barrier Reef could disappear in next 30 years after making startling discovery

Scientists have sounded the alarm about the Great Barrier Reef's demise after making a starling discovery.

They found that ocean temperatures around the natural wonder are now the hottest in at least 400 years, reaching 0.34 degrees Fahrenheit above the previous record high.

Researchers warned that if the warming continues, the iconic ecosystem could disappear in the next 30 years.

The findings were made by drilling the cores of coral to identify geochemical changes and reconstruct past sea-surface temperatures. 

'If humanity does not divert from its current course, our generation will likely witness the demise of one of Earth’s great natural wonders,' Benjamin Henley, the study's lead author at the University of Melbourne, wrote for The Conversation.

The research team, which spanned several Australian universities, analyzed long-lived corals in and around the reef.

These corals keep a record of ocean temperatures in their skeletons, which the researchers used to reconstruct sea surface temperatures from 1618 to 1995, alongside modern sea surface temperature measurements spanning 1900 to 2024.

Co-author Helen McGregor said it was like counting the rings of a tree to determine its age. 

Their research concluded sea-surface temperatures in the Coral Sea were relatively stable and cool for centuries before rapid increases to unprecedented levels recorded between January and March, posing a danger to the reef. 

The analysis revealed that ocean temperatures around the reef have climbed significantly since 1960, and five of the six hottest years on record occurred in the last decade.

'From 1960 to 2024, we observed annual average summer warming of 0.216F per decade,' researchers share in The Conversation. 

The researchers linked this temperature rise to human-driven climate change. 

'Right now the great barrier reef is in danger,' Henley told DailyMail.com.

'Severe mass bleaching events are likely to occur in the coming years.' 

Scientists have long said additional loss of coral is likely to be a casualty of future warming as the world approaches the 2.7F threshold that countries agreed to try and keep warming under in the 2015 Paris climate agreement. 

Even if global warming is kept under the Paris Agreement´s goal, which scientists say Earth is almost guaranteed to cross, 70 percent to 90 percent of corals across the globe could be threatened, the study's authors said. 

Australia's Great Barrier Reef is the world's largest coral reef system, covering 133,000 square miles- an areal larger than the size of Italy - off the coast of Queensland. It's so big that it's visible from space. 

This biodiversity hotspot is home to more than 9,000 known species, including 400 types of coral, 1,500 species of fish and 4,000 types of mollusks. 

It also supports tourism, fishing and other commercial industries. The total economic value of the reef is estimated at $56 billion, and it supports roughly 64,000 jobs.

But that could soon change, scientists warn. 

When ocean temperatures get too hot, it causes corals to expel the algae that lives in their tissues. 

This process, known as coral bleaching, turns corals completely white, deprives them of their main food source and makes them more vulnerable to disease.

Corals can survive bleaching, but they need time to recover, Henley said. He's concerned that the frequency of mass bleaching events could increase as ocean temperatures continue to rise. 

Having even one mass bleaching event per year would make it extremely difficult for corals to recover, he said, putting them at greater risk of death.

This summer, the Great Barrier Reef suffered its most extensive and extreme mass bleaching event on record, scientists at the Australian Institute of Marine Science said in a separate report published this week. 

It was the reef's fifth mass bleaching event in just eight years.

This study offers a new perspective on how rising ocean temperatures have impacted the Great Barrier Reef over the long term, and how they will continue to impact the reef into the future, Henley said. 

As climate change progresses, its affect on the Great Barrier Reef will be felt on both local and international scales, and in terms of both environmental and economic impacts

'It's a place of spectacular beauty, and it's ecologically unique,' Henley said, adding, 'It's a very special place, and we are losing it.'