Peter Dutton has rejected claims he does not believe in climate change, despite earlier saying he'd leave it to experts to decide if it was fuelling natural disasters.
Climate change became a policy focus during the second leaders' debate on Wednesday night, when the opposition leader was pressed on whether Australia was already seeing its effects.
While Mr Dutton agreed there was an impact from climate change, he did not say whether rising temperatures were making natural disasters worse.
"I'll let scientists and others pass that judgement," he said.
"I can't tell you whether the temperature has risen in (the flood-affected town of) Thargomindah as a result of climate change or that the water levels are up in Thargomindah's latest flood as a result of climate change."
The remarks were quickly seized upon by Prime Minister Anthony Albanese, who accused Mr Dutton of taking the coalition backwards on the issue.
"Does he believe in gravity?" Mr Albanese said
"I thought John Howard wasn't great on climate change, I gotta say that, but this guy's worse."
Mr Dutton later acknowledged the existence of the issue, using it to spruik his nuclear energy policy, which he said would help to reduce carbon emissions.
"I believe in climate change and that is a reality. It's why we've adopted our position in relation to net-zero by 2050," he told reporters in Maitland.
"We're the only party, through our energy policy, which is capable of delivering lower cost electricity and gas, reliable energy."
AAP FactCheck has previously investigated claims about climate change fuelling various natural disasters, finding there was evidence to show floods and droughts were getting worse in Australia and elsewhere.
Tropical cyclones have become less frequent, but research suggests they might be becoming more severe.
Australian Conservation Foundation chief executive Kelly O'Shanassy said Mr Dutton's comments were damaging.
"It's a serious concern that one of the candidates vying to be Australia's prime minister is unwilling to stand up and say climate change is real, is happening and is affecting Australia," she said.
It comes as a report from the Centre for Policy Development found while the federal government spends $1.6 billion on recovery from natural disasters, only $215 million is budgeted for.
Report co-author Guy Debelle said it would create a $6 billion gap over the next four years.
"Disasters are inevitable, not unpredictable. We know they're coming, we just don't know exactly when," he said.
