Mining magnate Andrew Forrest has slammed plans to develop a new gas field in the Timor Sea.

Last year, Santos bought the $4.7 billion Barossa gas field from ConocoPhillips. This marked the start of one of the largest Australian oil and gas investments in almost a decade, seeking to extract gas from under the Timor Sea, about 300 kilometres north of Darwin.

“Santos is about to kick off one of the most polluting projects in the world,” Mr Forrest said of the project this week. 

“It needs to be called for what it is. It is an atrocious project, an atrocious project."”

The former owners of the site, ConocoPhillips, stated in a project proposal to the federal regulator that the gas field would produce about 1.5 tonnes of CO2 equivalent for every tonne of LNG.

Santos has not revealed its own calculations of Barossa's carbon emissions, but has indicated it wants to reduce its carbon emissions by about 25 per cent on ConocoPhillips' estimates.

Even with that reduction, the proposed project has been described as “a carbon-dioxide emissions factory with an LNG by-product… [producing] more waste than product”.