Australia on Friday avoided having the Great Barrier Reef listed as an endangered world heritage site by UNESCO, despite extensive climate change-fuelled damage to the ecosystem's corals.

After a concerted lobbying effort by Canberra, members of the World Heritage Committee -- including leading fossil fuel producers Russia and Saudi Arabia -- voted to give Australian conservation efforts more time.

The group brushed aside UNESCO experts' recommendation that the reef's World Heritage status be downgraded because of dramatic coral decline, instead telling Australia to report on the reef's status by 2022.

The 2,300-kilometre-long (1,400-mile-long) ecosystem has suffered three mass coral bleaching events since 2016, caused by rising ocean temperatures due to global warming.

Areas once teeming with vibrant corals have become lifeless washed-out wastelands, and two-thirds of the reef is believed to have been damaged in some way.

Despite the damage, the reef remains a vital tourist draw for Australia, which had feared an "in danger" label could deter post-pandemic visitors.

Australia's environment minister Sussan Ley had flown to Paris earlier this month to personally lobby member states on the committee, while key ambassadors were invited on a reef snorkelling trip.

On Friday, Ley welcomed the decision, thanking "esteemed delegates for recognising Australia's commitment to protecting the Great Barrier Reef".

Environmental groups decried the decision as a political stitch-up.

"This is a victory for one of the most cynical lobbying efforts in recent history," said Greenpeace Australia Pacific CEO David Ritter.

The Great Barrier Reef is the world's largest living structure
The Great Barrier Reef is the world's largest living structure AFP / Sarah LAI

"This is not an achievement -- it is a day of infamy for the Australian government."

A decision on the reef's status had already been postponed from 2015, when Australia successfully waged a similar diplomatic campaign and committed billions of dollars to reef protection.

"This is history repeating itself," said Climate Council spokesman Will Steffen.

"Australia must stop censoring science, and start taking the steps we know are required to help protect the reef," he added.

Though Australian government scientists say corals have shown signs of recovery in the past 12 months, they admit the reef's long-term outlook remains "very poor".

As well as coral bleaching, the reef is also susceptible to damage from cyclones and outbreaks of crown-of-thorns starfish, which eat the coral.

UNESCO had accused Australia of failing to meet key water quality and land management targets, while also taking aim at the country's conservative government for its lacklustre climate efforts.

Canberra is facing growing international criticism for refusing to commit to net zero emissions by 2050.

The government has said it hopes to meet the target "as soon as possible" without harming the country's fossil fuel-reliant economy.

The World Heritage Committee asked UNESCO to send a monitoring mission to inspect the reef, after Canberra criticised the agency for relying on existing reports to make its recommendation.

The decision comes after Venice also dodged the endangered list on Thursday, following Italy's move to ban large cruise ships from sailing into the city centre.

However, Liverpool's waterfront was deleted from the list entirely, amid concerns about overdevelopment, including plans for a new football stadium.