Australia’s Great Barrier Reef is one of the seven natural wonders on our planet. It’s renowned for its beauty, diversity, spectacular marine wildlife and vibrant corals. The dazzling display of our coral reefs attracts millions of tourists who travel here from all over the world to witness this magnificent and unique reef system.

Globally, rising sea temperatures due to climate change threaten 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.

Already we’ve seen significant signs of coral bleaching on the Great Barrier Reef, showing that we need to act now on climate change. We don’t have a moment to lose.

Take #TimeOutForNature this Earth Hour, and as we reflect on the incredible benefits our oceans provide us and work together to protect it.


What is coral bleaching?


The vibrant colours of corals come from algae that live inside their tissues. This algae gives corals energy, allowing them to grow and flourish. However, when water temperatures are too hot for too long, corals expel the algae, which cause 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.

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.

How can we stop it?


Back-to-back mass bleaching events in 2016 and 2017 wiped out half of the shallow corals on the Great Barrier Reef. If carbon pollution isn’t reduced, climate change is expected to cause more frequent and severe coral bleaching on the Reef.

Coral reefs are incredibly resilient, but their full recovery can take decades. That’s why it’s crucial to take action and make a rapid shift towards renewable energy before it’s too late.



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This Earth Hour, we're calling on all Australians to sign up to switch off and join a worldwide community of millions taking #TimeOutForNature.