Climate Change Leads Great Barrier Reef to Suffer Record Coral Bleaching

Australia’s Great Barrier Reef has experienced its most severe coral bleaching on record, with researchers citing “climate change-induced thermal stress” as the main cause behind the widespread damage.

A report released on Wednesday by the Australian Institute of Marine Science (AIMS) revealed that two of the reef’s three regions, the northern and southern areas, saw the most significant annual decline in coral cover since monitoring began 39 years ago. In both regions, coral cover dropped by 25% to 33%, following several years of strong growth.

“We’re now seeing increased variability in hard coral cover,” said Dr. Mike Emslie, head of AIMS’s Long-Term Monitoring Program. “This is a trend that has unfolded over the past 15 years and reflects the growing pressure on the ecosystem.”

The Great Barrier Reef, the world’s largest living structure, stretches over 2,400 kilometres off the coast of Queensland in northeastern Australia. 

Since 2016, it has endured five mass bleaching events, where elevated sea temperatures cause corals to lose their vibrant color and become vulnerable to death.

The 2024 bleaching episode was especially devastating. According to the report, it had the most extensive impact ever recorded, with bleaching ranging from moderate to severe across all three reef regions.

Although the reef is not currently listed as a UNESCO World Heritage Site "in danger," the United Nations has recommended its inclusion due to the mounting ecological threats.

Australia has long resisted this designation, citing concerns over its impact on tourism. The reef contributes an estimated 6.4 billion Australian dollars (USD 4.2 billion) to the national economy each year.