Ocean temperatures off Australia's Great Barrier Reef have reached their highest level in 400 years over the past decade, researchers said today, warning that the reef, which has been repeatedly bleached by warm waters, is unlikely to survive if global warming not be stopped.
Between 2016 and 2024, this largest coral ecosystem in the world and one of the most biologically diverse, went through multiple bleaching events. This happens when the water becomes too warm, so the coral rejects the algae that supply it with color and food, and sometimes dies as a result.
Earlier this year, an aerial survey of an area of about 300 coral reefs off Australia's northwest coast found that bleaching had affected two-thirds of that number, NASA said.
Researchers from the University of Melbourne and other Australian universities published today in the journal Nature the results of a comparison of current water temperatures near the Great Barrier Reef with temperatures from the period from 1618 to 1995, which they reconstructed on the basis of coral skeletons. They enriched that finding with sea surface temperatures from 1900 to 2024.
Temperatures were mostly stable before 1900, and steady warming from January to March began in 1960.
During five of the last ten years when bleaching occurred - 2016, 2017, 2020, 2022 and 2024 - January to March temperatures were hotter than anything since 1618.
The researchers used climate models to compare the rate of warming after 1900 with human-induced climate change and found that the only year as warm as the critical five was 2004.
If the warming of the planet exceeds 1,5 degrees compared to the pre-industrial era, and scientists believe that this is a fairly certain scenario, between 70 and 90 percent of the world's coral reefs will be threatened, they say.
Regarding the Great Barrier Reef, it was reported that thermal extremes occur too often for corals to effectively adapt and survive, so if global warming is not curbed, "our generation will surely witness the destruction of one of the global wonders of the world," he wrote. is one of the main authors of the study published today by Benjamin Henley from the University of Melbourne.
Coral reefs are one of the main sources of seafood and are an economic resource. They also protect the coast from serious cannon storms.
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