PARIS — A United Nations-backed mission is recommending that the Great Barrier Reef be added to the list of endangered World Heritage sites, warning that without “ambitious, rapid and sustained” climate action the world’s largest coral reef is in peril.

The warning came in a report published Monday following a 10-day mission to the reef last March by officials from UNESCO and the International Union for Conservation of Nature.

The reef, a living place of immense variety and beauty on the north-east coast of Australia, has been on UNESCO’s World Heritage List since 1981.

Australia's federal government and Queensland's state authorities should adopt more ambitious emission reduction targets, in line with international efforts to limit future warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times, according to the report.

Feedback from Australian officials, both at the federal and state level, will also be reviewed before UNESCO, the U.N.’s Paris-based cultural agency, makes any official proposal to the World Heritage committee.

The text is damning about recent efforts to stop mass bleaching and prevent pollution from contaminating the reef’s natural waters, saying they have not been fast nor effective enough. Uncurbed emissions lead to increased water acidity, which can be toxic.

More money should be found to increase the water quality and stop the site’s decline, the report concludes.

In an email to AP, the U.N. cultural agency said: “In recent months, we have had a constructive dialogue (with) Australian authorities. But there is still work to be done.”