Great Barrier Reef bleaching to intensify by 2034

The Australian Climate Council warns that devastating bleaching will mean a "death sentence" for the Great Barrier Reef. The world's largest coral system is home to millions of marine life forms.

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Aerial look at the Great Barrier Reef in Australia — Image: picture-alliance/Imaginechina

According to a report published on Thursday, Australia's Great Barrier Reef is in danger of mass coral bleaching events as often as every two years, starting in 2034, unless greenhouse gas emissions are drastically reduced.

Located off the coast of Queensland, the Great Barrier Reef is the world's largest coral system and is one of the most diverse ecosystems on the planet, home to millions of marine life forms.

The Climate Council, an Australian non-profit working on environmental issues, released the report, highlighting that rising sea surface temperatures over the past century had led to more frequent and prolonged global marine heat waves.

"By 2034, the extreme ocean temperatures that led to the 2016 and 2017 bleaching events may occur every two years," the report said, warning that "such a short period between bleaching events is not sustainable as the development of coral assemblages takes at least a decade."

The Great Barrier Reef's bleaching event of 2016 and 2017 resulted in the death of 30 percent of corals overall and as much as 75 percent in some areas.

Lesley Hughes, the head of Climate Council and an ecology professor, rang the alarm, asserting that if the two-year recurring bleaching were to occur, it would "effectively sign the death certificate for the world's largest natural living wonder."

Corals affected by bleaching in 2016 at the Great Barrier Reef Image: picture-alliance/Kyodo

Climate change to blame

The report stressed that the survival of coral reefs around the world, including the Barrier Reef, depends heavily on how deeply and swiftly greenhouse gas pollution levels are lowered in the coming years.

The Climate Council noted that global sea surface temperatures have increased by 0.2 degrees Celsius from 1992 to 2010 and in turn, the odds of more frequent and prolonged marine heat waves have also risen.

"Intensifying marine heatwaves around the world are now occurring more often, lasting longer and are more intense than ever before," the report said.

"In the 1980's, we would see a 27-year gap on average in between bleaching events around the world. Now, they're hitting every six years on average," Hughes asserted.

Martin Rice, chief executive of Climate Council, said that limiting global temperature rise to no more than 1.5 degrees Celsius, as agreed during the Paris climate deal, would be a critical step to ensure the survival of reefs worldwide.

Great Barrier Reef under threat

The Great Barrier Reef is one of Australia's top tourist destinations and generates some 6.4 billion Australian dollars ($4.7 billion or €4 billion) a year, providing more than 64,000 jobs.

But in recent years, the reef has suffered from a crown-of-thorns starfish epidemic, sedimentation, degradation of water quality, ocean acidification, and massive bleaching events.

In May, the Australian government announced a plan to spend 500 million Australian dollars ($380 million) to help restore and protect the reef in the coming years. The conservation plan would also seek to improve water quality.

But Australia has fallen short of its climate goals and remains a top polluter, with one of the highest per-capita emission rates in the world. In 2017, the country's greenhouse gas emissions increased for a third consecutive year, approaching an all-time high.

jcg/msh (dpa, EFE)