It is the largest living structure on earth. And has been around for 600,000 years. But new research out today, shows that the Great Barrier Reef is experiencing the highest ocean heat in 400 years. And this comes after five mass coral bleaching events.

So why has the UNESCO World Heritage committee decided against putting Australia’s most famous environmental landscape on the 'in danger' list? For the third year in a row?

Today, climate and energy correspondent, Mike Foley, on the politics that are putting the Great Barrier Reef close to a point of no return.