Scientists warn of Great Barrier Reef extinction as ocean temperatures reach to highest levels in 400 Years

The Great Barrier Reef (Image: Canva)

A new study exposes that ocean temperatures around Australia's Great Barrier Reef have surged to their highest levels in 400 years over the past decade, posing a grave threat to this world-renowned ecosystem.

Impact of Human-Induced Climate Change
Published on Thursday, the research highlights the impact of human-induced climate change on the Great Barrier Reef, the largest living structure on Earth. Stretching approximately 2,400 kilometres off the coast of Queensland, the reef has seen significant warming since the early 20th century.

Scientists from Australian universities analysed coral cores, similar to counting tree rings, to gauge summer ocean temperatures dating back to 1618. Combining this historical data with ship and satellite records from the last century, the study reveals that temperatures remained stable until around 1900, when human activities began causing significant rises.

Consequences and Economic Significance
From 1960 to 2024, researchers observed an average annual warming of 0.12°C per decade from January to March. Since 2016, the reef has endured five mass coral bleaching events, which coincide with five of the six warmest years in the past four centuries. These bleaching events occur when corals expel the algae providing them with colour and nutrients due to heat stress, leading to an increased risk of death.

Reef fish swim over coral colonies that are recovering on the Great Barrier Reef off Cairns, Australia, on October 25, 2019. (Image: REUTERS)

"The world is losing one of its icons," said Benjamin Henley, a University of Melbourne academic and co-author of the study. "It’s deeply troubling to see this happen within our lifetime. It’s very, very sad."

The Great Barrier Reef not only stands as a natural marvel but also plays a crucial role in Australia's economy, contributing A$6.4 billion (US$4.2 billion) annually through tourism. Coral reefs also protect shorelines from erosion and support thousands of marine species.

However, if global warming continues unchecked, the reef’s future remains in jeopardy. The United Nations has suggested adding the Great Barrier Reef to the list of world heritage sites in danger, a recommendation Australia has resisted due to potential negative impacts on tourism.

Lissa Schindler, Great Barrier Reef campaign manager at the Australian Marine Conservation Society, stressed the need for enhanced climate action. "Australia must increase its ambition, action, and commitments to combat climate change and safeguard our greatest natural asset," she said.

The study underscores the urgent need for global cooperation to address climate change and preserve the Great Barrier Reef for future generations.