The North West Shelf is a sprawling industrial complex of offshore rigs, undersea pipelines and processing factories pumping out more than 10 million tonnes of liquified gas and petroleum each year.

Run by resources giant Woodside, it is one of the world's largest producers of liquified natural gas -- and one of Australia's biggest polluters.

Originally slated to close in five years' time, Environment Minister Murray Watt on Friday approved an extension to keep it running until 2070.

Watt said he approved the extension "subject to strict conditions" designed to limit the impact of its emissions.

Leaders in neighbouring Pacific islands, already seeing coastlines eaten away by rising seas, had urged Australia to shut the plant down.

"Pacific leaders have made it clear -- there is no future for our nations if fossil fuel expansion continues," said Tuvalu Climate Change Minister Maina Talia.

"The North West Shelf extension would lock in emissions until 2070, threatening our survival and violating the spirit of the Pacific-Australia climate partnership," he said this week.