The Great Barrier Reef off the east coast of Australia will be largely destroyed by 2050 because of rising sea temperatures, according to a new report.
The reef is teeming with marine life
Researchers from Queensland University's Centre for Marine Studies said there was little evidence that corals could adapt quickly enough to cope with even the lowest projected temperature rise of 2C.
Over-fishing and water pollution were also contributing to the destruction of coral on the reef.
The new study predicts that within about 15 years the Barrier Reef tourist and fishing industries will lose thousands of millions of dollars and many thousands of people will be forced out of work.
By the middle of this century, less than 5% of the reef coral will remain alive.
Most of the colourful fish for which the reef is also famous will disappear.
Entitled Implications Of Climate Change For Australia's Great Barrier Reef, the study was commissioned by the Worldwide Fund for Nature, and was paid for in part by the Australian government.
"Under the worst-case scenario, coral populations will collapse by 2100 and the re-establishment of coral reefs will be highly unlikely over the following 200-500 years," it said.
Coral becomes highly stressed by changes in sea temperature of even one degree and the predicted temperatures along the reef will rise by up to six degrees by the end of the century.
GREAT BARRIER REEF
More than 2,000km long
Home to 1,500 types of fish
Only living thing the naked eye can see from space
"Reefs will not disappear but they will be devoid of coral and dominated by other less appealing species, such as seaweed," the report said.
The Great Barrier Reef injects an estimated $975m into the economy each year through tourism and fishing.