Global warming puts 99% of Great Barrier Reef coral at risk, study finds

Australia’s spectacular marine feature could almost cease to exist unless global warming is brought under control

The world’s most extensive and spectacular coral reef ecosystem, the Great Barrier Reef, faces large-scale destruction with almost 70 to 99 per cent of coral at risk if global warming continues to rise.

A report by the Australian Academy of Science recently said the Paris Agreement to keep global warming at 1.5°C above pre-industrial levels “has now slipped out of reach and is virtually impossible".

The report also said that Australia had warmed by 1.4°C and if this kept up, the reef would not last long.

The Great Barrier Reef, stretching for 2,300 kilometres along the north-eastern coast of Australia, has lost more than half of its coral in the past three decades.

Coral bleaching in 2016, 2017 and 2020 has further damaged its health and affected its animal, bird and marine population, the International Union for Conservation of Nature said.

Bleaching occurs when hotter water destroys the algae that the coral feeds on, causing it to turn white.

The report also found that if Australia warmed up to 2°C, only 1 per cent of the reef is expected to survive.

Scientists say the surviving corals would be able to return and cover the reef if the warming is halted.

Global warming will also cause other famous ecosystems, such as the World Heritage-listed Kakadu National Park in Far North Queensland, to be affected tremendously.

The report further warns that at 3°C above pre-industrial levels, many of the country’s ecological systems would be destroyed.

The International Union for Conservation of Nature has moved the reef’s status to critical and deteriorating on its watch list.

Some activities that threaten it, such as fishing and coastal development, can be tackled by the management authorities, the union said.

Progress towards protecting the reef under a long-term sustainability plan to 2050 has been slow, and it has not been possible to stop its deterioration, the union said.

But scientists have been involved in various individual projects aimed at improving the reef and helping to protect it.

Coral from Australia’s first “Coral IVF” trial on the Great Barrier Reef in 2016 have survived recent bleaching events and are on track to spawn this year, researchers say.

Peter Harrison, director of Southern Cross University’s Marine Ecology Research Centre, led the development of a larvae restoration technique that involves collecting coral sperm and eggs during the annual mass spawning on the reef.

The project, in conjunction with the Great Barrier Reef Foundation, has re-established 60 coral-reproducing populations on the reef through the programme.