Adelaide would host a major global climate conference in 2026, as long as Australia's bid is successful and Peter Dutton loses the federal election.
The opposition leader has promised to ditch Australia's attempt to host the United Nations climate summit COP31 alongside Pacific Island neighbours.
That would be "ridiculous", Prime Minister Anthony Albanese said on Monday.
Not only would the conference help repair relationships with Pacific Island nations dismayed by the former coalition government's stance on climate change, it would also provide a boost to the local economy, he said.
"If Peter Dutton is elected, you can see him copying policies from other jurisdictions and pulling out of (climate accord) Paris," Mr Albanese told reporters in Adelaide.
"We know a whole lot of their mob are still in climate denial."
The host of COP31 will be announced at this year's event in November, but Australia's bid could be scuppered if the coalition wins the election on May 3.
Mr Dutton in late March called the bid "madness", arguing it would cost tens of billions of dollars at a time when people were struggling with the cost of living.
Wesley Morgan, a research associate with UNSW's Institute for Climate Risk and Response, said Mr Dutton would face a frosty reception from Pacific Islands leaders if he abandoned the push, diminishing Australia's influence in the region.
"Palau, in particular, could embarrass Dutton on the global stage," Dr Morgan said.
"It will host the Pacific Islands Forum meeting next year, weeks before the COP31 talks."
Australia's physical and economic security would be set back by pulling out of the bid, said James Bowen, an energy and climate expert who runs consultancy ReMap Research.
"Dutton's perspective is short-sighted in the extreme," he said.
"The costs of hosting COP31 could be a bargain compared with the massive strategic and economic windfall they could deliver."
Alongside South Australian Premier Peter Malinauskas, the prime minister confirmed Adelaide as his preferred host city, if the bid was successful.
The SA Labor government has been lobbying to host the conference, adding another event to its stacked line-up and cementing its reputation as the Festival State.
Still coming down from the heavy loss his AFL team Hawthorn suffered the previous night at the hands of Mr Malinauskas's team, Port Adelaide, Mr Albanese congratulated the premier for the success of Gather Round held over the weekend.
"Gather Round is just one example," he said.
"(Mr Malinauskas) is putting Adelaide on the map as a global city.
"I can't think of anywhere better than Adelaide to host that event."
South Australia derives nearly 80 per cent of its energy from renewables and is on track to be at 100 per cent by the end of 2027, Mr Malinauskas said.
"It gives us a chance to showcase not just to the rest of the country, but to the rest of the world, that thoughtful transition around energy is actually an economic opportunity more than anything else," he said.
