Plagues of venomous crown-of-thorns starfish, which eat coral, have also caused widespread damage.
A plan to save Australia's Great Barrier Reef from destruction has been announced as Prime Minister Tony Abbott sought to persuade the United Nations that the World Heritage site was not in danger.
The reef has lost about 50 per cent of its coral in the past 30 years, partly
because of ocean acidification caused by greenhouse gas emissions, the dumping of spoil from the dredging of sea channels, and pollution from agricultural chemicals. Plagues of venomous crown-of-thorns starfish, which eat coral, have also caused widespread damage.
Abbott once dismissed climate change as "absolute crap" and despite later admitting it was a real issue, has continued to be criticised for his Government's stance on environmental matters.
A draft of the Government's 2050 Long-Term Sustainability Plan for Great Barrier Reef was condemned for failing to mention climate change, but the final version admits this is "the most significant threat".
Speaking to reporters, Abbott said global warming was "relevant for all reefs including this, the world's greatest reef ... we're making our position clear right around the world - this is a number one priority of the Australian Government: to protect the Great Barrier Reef".
