World’s Largest Coral Reef System-The Great Barrier Reef Under Threat Of Mass Bleaching

The Great Barrier Reef, the world’s largest coral reef system, may be entering an unprecedented 4th mass bleaching in 6 years. This comes as UNESCO delegates visit the Reef this week to assess whether it should be considered World Heritage ‘in danger’ due to climate change, as scientists had previously recommended.

Australia last year managed to postpone a downgrade of the World Heritage site after lobbying led to UNESCO postponing a decision to this year (following this visit).

Bleaching does not immediately kill coral reefs, but it leaves them more vulnerable to dying. It usually takes several years for coral to recover from bleaching, which makes repeated bleaching events – as we may now be seeing – particularly dangerous. Mass bleaching had never been recorded on the reef before 1998.

The Great Barrier Reef Marine Park Authority has stated that “Bleaching has been detected across the Marine Park — it is widespread but variable, across multiple regions, ranging in impact from minor to severe.”

Terry Hughes, Distinguished Professor at the Australian Research Council Centre of Excellence for Coral Reef Studies, and a leading expert on the Great Barrier Reef, has said that the reef is now already experiencing a 4th mass bleaching event since 2016.

The Climate Council, an Australian climate organisation, has also released a report, stating that over the past year, excess heat absorbed by the ocean was equivalent to seven Hiroshima atomic bombs detonating every second. Bleaching could occur every year if warming continues, which would lead to the effective death of the reef.

Tropical coral reefs are gravely threatened by climate change, according to the recent IPCC climate report. Tropical coral reefs face 70-90% declines if global temperatures rise to 1.5°C, and will see 99% declines if warming continues to 2°C. Current emission policies and commitments put the world on course for warming of about 2.3-2.7°C.

Australia’s climate policies are ‘highly insufficient’ for limiting warming, according to Climate Action Tracker, and – if replicated by other countries – would lead to 3-4°C warming. The country is one of the top two exporters of coal in the world.Australia’s climate policies and commitments are not Paris Agreement Compatible. Australia’s 2030 domestic emissions reduction target is consistent with warming of 4°C if all other countries followed a similar level of ambition. Under Australia’s current policies, emissions will continue to rise and are consistent with more than 3°C warming. Australia needs to set a more ambitious target for emissions reductions.

The writer of this article is Dr. Seema Javed, a known Environmentalist, Journalist and Communications Expert