Labor says Tony Abbott is calling the shots on the federal government's energy policy, after the former prime minister used a speech in London to applaud scepticism about climate change.
On Monday night, Mr Abbott told the Global Warming Policy Foundation the world should beware the words "the science is settled", likening those who wanted action to tackle climate change to religious zealots and "thought police".
"Primitive people once killed goats to appease the volcano gods," he said.
Labor leader Bill Shorten told reporters in Brisbane on Tuesday the former Liberal leader who once ousted Malcolm Turnbull over climate policy had "lost the plot".
"We see Turnbull is paralysed by fear and infighting in the Liberal Party and he can't do anything meaningful - meanwhile Australia has an energy price crisis and an energy supply crisis."
One of Mr Abbott's coalition colleagues, former resources minister Matt Canavan, disagreed with the former prime minister's scepticism about climate change.
"I accept there is a link between carbon dioxide emissions and the warming of the atmosphere (but) ... there are often exaggerated and overhyped claims made," Senator Canavan told Sky News.
"We can become more carbon efficient, but we can do it by becoming more efficient on all fronts - power production and transport."
He agreed with Mr Abbott the renewable energy target had been a "disaster", but given it was on track to finish in 2020 there was no point in abolishing it immediately.
Senator Canavan said the government was right to "modify" the proposal put by Chief Scientist Alan Finkel for a clean energy target, arguing the basis of the Finkel report's modelling on prices was "rubbery at best".
"We are going to put a priority on making sure we keep affordability for Australians - that is the only sustainable policy.
"Eventually there is a thing called an election and they will kick the government out that is not producing the outcomes they want, which is lower power prices."
Mr Shorten said the opposition was willing to discuss a long-term climate and energy policy with the government.
"Let's try a new way. Let's back in renewables, let's back in the gas industry as a transition and let's put downwards pressure on prices," the Labor leader said.
But Senator Canavan cast doubt on Mr Shorten's offer.
"He is not [willing to compromise] because they are holding out a blanket opposition to any new coal-fired power stations."
Mr Abbott told the Global Warming Policy Foundation's annual lecture that extreme weather events were not getting worse, but did more damage because there is "more to destroy", and that a "gradual lift in global temperatures" may be benefitial, according to a speech posted on the think tank's website.
In the wide-ranging speech, Mr Abbott warned against the economic harm of climate-change policies.
"Environmentalism has managed to combine a post-socialist instinct for big government with a post-Christian nostalgia for making sacrifices in a good cause," Mr Abbott said.
The Global Warming Policy Foundation was established by climate sceptic Nigel Lawson, who is a former minister in then prime minister Margaret Thatcher's Conservative government.
The member for Warringah also touched on Australian politics, saying the Liberal Party lost seats in the 2016 federal election because it hadn't responded to Labor's 50 per cent renewable energy target promise.
Mr Abbott's speech comes as the Turnbull government appears to be abandoning a clean energy target, one of Chief Scientist Alan Finkel's recommendations.
Energy Minister Josh Frydenberg told an energy summit on Monday the government was considering its new policy against a backdrop of the rapidly falling cost of renewables and storage, greater efficiencies being found in thermal generation and the need for sufficient dispatchable power.
In 2013, former prime minister John Howard told the annual lecture an international agreement on emissions would never be reached and Mr Abbott's own election victory was in part a backlash to "overzealous action" on global warming.
Cardinal George Pell has also spoken to the think tank.
Mr Abbott's comments attracted furore on social media, with one Twitter user writing "Tony Abbott has never been one to let the facts get in the way of his ideology".