A Liberal senator who felt unsettled by the facts of climate change has become a laughing stock after admitting on ABC’s Q&A he was “not relying on evidence” to form an opinion.

Senator Jim Molan’s comments easily became the highlight of the year’s first episode of the current affairs panel show, which welcomed new host Hamish Macdonald.

When Mr Molan was repeatedly pressed on whether he thought humans were responsible for climate change, the retired Army Major General said he was “open” to that idea.

“I accept the climate is changing. It has changed and it will change. What it’s producing is hotter and drier weather and a hotter and drier country,” he said on Monday night.

“As to whether it is human-induced climate change, my mind is open.”

Sitting opposite Mr Molan was Michael Mann, one of the world’s leading climate scientists, geophysicist and climatologist.

Professor Mann warned that Australia’s weather conditions could worsen if it did not join global efforts to reduce carbon emissions.

“Every scientific institution in the world that’s weighed in on this matter, climate change is real,” Professor Mann said.

“It’s human-caused. It’s already leading to disastrous impacts here in Australia and around the rest of the world. And it will get much worse if we don’t act.”

Mr Molan went on to say “Michael might say that the science is settled”.

“And I respect very much scientific opinion but every day across my desk comes enough information for me to say that there are other opinions.”

Macdonald asked him once again “what is the evidence you are relying on?” to which the Senator responded, “I’m not relying on evidence, Hamish”.

The criticism quickly piled on. Not only was Mr Molan heckled by the crowd, but parliamentary peers and commentators took to social media to condemn the senator.

“Oh dear Jim Molan, it’s gone from a car crash to a train wreck,” Senator Jacquie Lambie tweeted.

Oh dear @JimMolan its gone from a car crash to a train wreck #qanda #ClimateEmergency

— Jacqui Lambie (@JacquiLambie) February 3, 2020

For god sake @JimMolan you’re not in the Army anymore –
speak the bloody truth! #qanda #climatemergency

— Jacqui Lambie (@JacquiLambie) February 3, 2020

The Australian Academy of Science tagged Mr Molan on Twitter to an “easy-to-understand” explainer about climate change science.

Hi @JimMolan. We have a Q&A that explains the #science of #climatechange in clear & easy-to-understand language and which aims to address confusion created by contradictory information in the public domain. Read it here: https://t.co/ePaoZqxw75 @QandA #QandA @hamishNews #auspol

— Australian Academy of Science (@Science_Academy) February 3, 2020

While retired Labor senator Doug Cameron called Mr Molan “an absolute joke”.

“I crossed swords with him on many occasions before I retired from the Senate. He talks about govt strategy however there was no strategy. Only reactive panicked response after ignoring scientific advice and pissing off to Hawaii on holiday,” he tweeted.

Jim Molan is an absolute joke on Q&A. I crossed swords with him on many occasions before I retired from the Senate. He talks about govt strategy however there was no strategy. Only reactive panicked response after ignoring scientific advice and pissing off to Hawaii on holiday.

— Doug Cameron (@DougCameron51) February 3, 2020