Australia’s Great Barrier Reef is one of the seven natural wonders on our planet, but climate change is pushing it to its limits, and the Reef is in danger. 


The fourth global mass bleaching event was confirmed, the second in ten years. This is the fifth mass bleaching event the Great Barrier Reef has experienced in just eight years, and the 2024 event is feared to be the most widespread and damaging to date.

“The coral crisis is a climate crisis. We must act urgently to stop burning fossil fuels or we will lose coral reefs worldwide.” - Pepe Clarke, WWF Oceans Practice Leader.

Read the full story here.

The Great Barrier Reef is the largest coral reef system and the biggest living structure on the planet. It’s renowned for its beauty, diversity, spectacular marine wildlife and vibrant corals. The dazzling display attracts millions of tourists who travel from all over the world to witness this magnificent and unique reef system.

But rising sea temperatures due to climate change threatens all of that. It’s estimated that half of the world’s coral reefs have been lost to coral bleaching over the last 30 years.

Sunlight illuminating coral= Great Barrier Reef
© Troy Mayne

What is coral bleaching?

The vibrant colours of corals come from algae that live inside their tissues. It gives corals energy, allowing them to grow and flourish.

When water temperatures are too hot for too long, corals expel the algae (zooxanthellae) which causes them to turn white.

Though they can recover from bleaching, if bleached corals are exposed to warmer water for eight weeks or more, they become vulnerable to diseases and begin to die. 

Bleached coral on Lizard Island= Queensland
© WWF-Aus / Alexander Vail

Causes of coral bleaching

Coral bleaching is the ghostly face of climate change. Corals are paying the price for our reliance on mining and burning fossil fuels like coal and gas.

As carbon pollution is emitted into Earth’s atmosphere, it traps heat and causes temperatures to rise. The ocean then becomes warmer, resulting in heatwaves that cause stress to corals.

Ocean heatwaves can destroy entire reef ecosystems and the marine life that depend on healthy, thriving corals. 


For the first time researchers recorded severe coral bleaching events on coral reefs in every region of the world, with 16% of corals killed around the world. Half the reefs on the Great Barrier Reef were impacted.


The Great Barrier Reef suffers another mass bleaching event. As coral bleaching became an issue of world concern, universities and research institutes strived to learn more.


The second global mass coral bleaching event hit the world’s reefs. Luckily, the Great Barrier Reef avoided extensive damage.


As ocean temperatures continue to rise, experts declared the third global bleaching event was underway and that it had started in mid-2014.


The largest die-off of corals ever recorded on the Great Barrier Reef, with an area roughly 1,100km long affected. By February 2016 The National Oceanic and Atmospheric Administration (NOAA) confirmed we were experiencing the longest global coral bleaching event ever observed.


The Reef suffered mass coral bleaching for a shocking second year in a row. The fragile corals were then hit by devastating winds caused by Tropical Cyclone Debbie and polluted floodwaters. In just two years, an estimated two-thirds of the Reef’s corals were damaged.

2019 and beyond

Back-to-back mass bleaching events in 2016 and 2017 wiped out half of the shallow corals on the Great Barrier Reef. The 2024 coral bleaching event is feared to be the most widespread and damaging to date.

Surveys showed that in the past two decades, 91% of corals were found to have been bleached at least once.

So, what does the future look like for the Great Barrier Reef? Though corals have a good capacity to bounce back from bleaching, it can take decades for them to fully recover after severe bleaching events. As Earth’s climate continues to rise and severe weather events occur more frequently, carbon emissions must be curbed if we’re to ensure protection for the Great Barrier Reef.

Large export vessels are loaded with coal and other cargo at the Gladstone Port. Queensland, Australia.
© WWF / James Morgan

Coral, coal and climate change

Australia’s energy needs are largely met by fossil fuels, including coal, oil and gas. But our reliance on these energy sources is placing the Great Barrier Reef in danger of extinction.

The mining and burning of fossil fuels contributes to our warming climate, trapping heat within our atmosphere and causing ocean temperatures to increase and corals to bleach.

If carbon pollution isn’t reduced, climate change is expected to cause more frequent and severe coral bleaching on the Reef.

That’s why it’s important to take action and make a rapid shift towards renewable energy before it’s too late.

Renewables Australia

What WWF is doing

A green turtle (Chelonia mydas) having a rest at Lighthouse Bommie= Great Barrier Reef
© Mike Ball Dive Expeditions / WWF-Aus

Regenerative Saltwater

Regenerative Saltwater is WWF-Australia’s plan to protect oceans and species in the southern hemisphere.

Our vision is for Australia to become a global leader in protecting oceans and species that sustain ecosystems and communities.

We are rallying to unite key southern hemisphere countries to create safe passages for marine wildlife, support coastal communities and protect 100 million hectares of ocean.

Regenerative Saltwater
© Shutterstock / Circotasu / Constantin, © Pond5 / CleverArts / WWF, © Bluebottle Films / WWF-Australia, © WWF-Australia, © WWF-Australia / Virtual Connexion

Regenerative Sky

To save the species, places, and communities we love, we must do everything possible to keep global heating at 1.5°C above pre-industrial levels.

Regenerative Sky (Climate) is our program of work to build a healthy and resilient net-zero world. Our vision is to support Australia to become a global leader in securing a healthy climate powered by communities, nature and renewable energy.

Read our climate strategy