Australian conservationists have launched a legal bid to block a massive gas project, saying it would harm the Great Barrier Reef by warming the planet.

Claiming gas giant Woodside Energy's Scarborough project would generate 1.37 billion tonnes of greenhouse emissions and likely harm the World Heritage-listed reef, the Australian Conservation Foundation applied on Tuesday for an injunction to halt the work.

The proposed, Aus$16 billion ($11 billion) Scarborough project would be located off the coast of Western Australia, thousands of kilometres from the Great Barrier Reef.

But the foundation argued gas drilled from Scarborough would fuel climate change to such an extent -- raising global temperatures by 0.0004 degrees Celsius (32 Fahrenheit) -- that it would have a "significant impact" on the natural wonder.

Climate change stress has already caused four "mass bleaching" events on the Great Barrier Reef since 2016, including this year when 91 percent of its corals were drained of their vibrant colours.

"Scarborough's gas is a climate bomb about to be detonated," said Australian Conservation Foundation Chief Executive Kelly O'Shanassy.

"We must not fall for the accounting trick that suggests these emissions won't affect reefs in Australia simply because the gas will mostly be burned overseas," she said.

The foundation argued gas drilled from Scarborough would fuel climate change to such an extent it would harm the Great Barrier Reef
The foundation argued gas drilled from Scarborough would fuel climate change to such an extent it would harm the Great Barrier Reef Great Barriier Reef Marine Park via AFP

"The reef is not concerned with the source of the greenhouse gases that damage it."

The foundation's projections for the climate impact of Scarborough, drawn from research by non-profit Climate Analytics, were significantly higher than Woodside's estimate of 878 million tonnes, which was approved by the regulator.

Woodside's chief executive Meg O'Neill said the company would "vigorously defend" itself against the court proceedings.

She said the project had received all primary environmental approvals and was "proceeding to schedule".

The lawsuit was lodged as Greenpeace Australia released a report on Wednesday about Woodside's Burrup Hub, of which the Scarborough gas project is a part.

Greenpeace claimed a "credible" spill scenario could reach the West Australian coast and as far north as Indonesia, concluding that the Burrup project was "too risky to proceed" because of the climate impact and Woodside's safety record.

A Woodside spokesperson said the company "has an established track record of safe and reliable operations".