Federal Environment Minister Sussan Ley says the government was “blindsided” by the report by UNESCO’s World Heritage Committee, which cited successive reef bleaching events as being of particular concern.

The long term outlook for the reef had deteriorated from “poor to very poor”, the draft decision says, but the government strongly opposes the move which could put its world heritage status at risk, impacting tourism and other ventures.

“It is a backflip on previous assurances, it is a deviation from normal process and it’s based on just a desktop review without the latest information,” Ley told ABC radio on Tuesday.

She agreed climate change was the biggest threat to the reef but said Australia had the best reef management practices in the world.

Australia’s views on the draft decision were made “very clear” to the Director General of UNESCO by Ley and Foreign Minister Marise Payne during a phone call on Monday night.

“We will contest this flawed approach, particularly because it’s sending a poor signal to those nations who are not making the investments in reef protection that we are making,” Ley said.

However the decision did not come as a shock to James Cook University’s Terry Hughes who said UNESCO has been moving toward linking the climate change polices of individual countries to stewardship of their world heritage sites.

“This draft decision, which will be ratified in July by the World Heritage Committee, is a logical one and one that isn’t terribly surprising,” Prof. Hughes told ABC radio on Tuesday.

He said there was a difference between just admitting climate change was the single biggest pressure on the reef and taking action to reduce it.

“Australia is still refusing to sign up to a net zero target by 2050 which makes it a complete outlier,” he said

“This draft decision from UNESCO is pointing the finger at Australia and saying, if you’re serious about saving the Great Barrier Reef, you need to do something about your climate policies.”

The UNESCO recommendation means it’s critical for countries, including Australia, to limit global temperature increases to 1.5 degrees, the World Wide Fund for Nature’s head of oceans in Australia, Richard Leck, said.

“Clearly, the significant coral mortality has prompted UNESCO to urge the Australian government to do more on climate,” he said.

The UNESCO committee draft report “strongly invites” the government “to undertake actions to address climate change under the Paris agreement” to reduce global greenhouse gas emissions.