About a month ago, a fake obituary was written for the 25 million year old Great Barrier Reef. It was a bit of performance art designed to shock, but there was a current of desperate urgency running through it — don’t let this natural wonder disappear, it warned. 

Now, that warning is much harder to dismiss. 

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The Great Barrier Reef recently sustained its largest loss in recorded history. Two-thirds of the reef’s 430-mile shallow northern stretch has died off, baked and bleached under blistering temperatures. The lower portion of the reef, a 1,400-mile stretch, was shielded from this die-off because a freak cyclone cooled temperatures. 

Coral reefs are incredibly fragile and complex systems that are the bedrock of many ecosystems around the world. Countless lifeforms — microorganisms, plants, animals — depend on reefs and they all work harmoniously to create a vibrant whole.

But even slight changes in water temperature can disrupt the intricate processes that allow them to thrive. These changes can eventually cause an entire system to collapse. With climate change accelerating around the world, temperatures are on a steep upward slope.

And it turns out oceans are bearing the brunt of climate change. The oceans absorb much of the extra heat generated in the global atmosphere. They also absorb a significant amount of the carbon produced from human activities, which, in huge quantities, acidifies the water. 

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Taken together — rapid warming and acidification — makes it hard for reefs to survive. And since both trends will continue in the decades ahead, the future is grim. 

Following this latest discovery, the Australian government committed an additional $33.6 million (45 million Australian dollars) for the Great Barrier Reef to improve water quality and reduce sediment runoff.

“[But] spending $45 million to improve water quality on the reef is like putting a Band-Aid on a person who has cancer,” said William Steffen, a climate scientist at the Australian National University school of medicine, biology and the environment, told The New York Times. 

Coral across Australia's Great Barrier Reef has suffered its most devastating die-off on record https://t.co/NKLfFuR7S8pic.twitter.com/3B88ke0JuH

— CNN (@CNN) November 29, 2016

In other words, unless you can replace all the water in the oceans with colder water, then there’s not much to be done for the reefs. Warming temperatures are a line that can’t be crossed — irreversible shifts have already been set in motion. 

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The Great Barrier Reef is not alone, either. All around the world, reefs are suffering. In Hawaii, for example, temperature rises of more than 4 degrees Fahrenheit in recent years have caused enormous die-offs and the future of many reefs seems unlikely. 

There are, however, some strains of coral reef that can better withstand temperature changes. Some scientists are working to universalize these properties by inserting them into vulnerable reefs to make them more resilient. 

But the clock is quickly running out. Soon, many reefs could be relegated to exhibits in museums, alongside actual obituaries