Great Barrier Reef Waters Record Hottest Temperatures In Four Centuries

Researchers have found that ocean temperatures in the Great Barrier Reef have reached their highest levels in 400 years over the past decade. They warn that the reef may not survive if global warming continues unchecked, according to the Associated Press (AP).

From 2016 to 2024, the Great Barrier Reef experienced several mass coral bleaching events. These events occur when water temperatures rise too high, causing corals to expel the algae that provide them with colour and nutrients, often leading to coral death.

Aerial surveys conducted earlier this year revealed significant bleaching in shallow waters across two-thirds of the reef. This was observed in over 300 reefs along Australia's northeast coast, as reported by the Great Barrier Reef Marine Park Authority.

Researchers from Melbourne University and other Australian universities published a paper on Wednesday in the journal Nature. They compared recent ocean temperatures with historical data using coral skeleton samples from the Coral Sea. This allowed them to reconstruct sea surface temperature data from 1618 to 1995 and combine it with data from 1900 to 2024.

The study showed largely stable temperatures before 1900, followed by consistent warming from January to March between 1960 and 2024. During five years of coral bleaching in the past decade—2016, 2017, 2020, 2022, and 2024—January and March temperatures were significantly higher than any recorded since 1618.

Impact of Human-Caused Climate Change

The researchers used climate models to attribute the post-1900 warming rate to human-caused climate change. The only year nearly as warm as those during the mass bleaching events of the past decade was 2004.

The Great Barrier Reef is an economic asset for its region and provides protection against severe tropical storms. However, there is growing concern about significant species loss and a reduction in the area covered by this vast reef as more heat-tolerant corals replace less heat-tolerant species.

"The Great Barrier Reef serves as an economic resource for the region and protects against severe tropical storms," researchers noted.

Without intervention to halt planetary warming, experts fear that this natural wonder may not endure future environmental changes.

With inputs from WAM