"This has been man-made, this fear mongering about climate change," Senator Hanson told Nine's Today on Tuesday.
"If climate change is happening, it is not because man is causing it to happen."
The Queensland senator claimed volcanic eruptions and oceans caused more carbon emissions than man-made pollution.
"There has been changes. What happened to the dinosaurs, how did they die off? Humans didn't create it," she said.
"We have volcano eruptions that actually spew out more carbon emissions and even the oceans do."
Senator Hanson said there was "no scientific fact" about the impact climate change was having on Queensland - despite a wealth of credible, peer-reviewed research on the topic.
"There's no peer review of these scientists," she said.
Senator Hanson also appeared to question the Bureau of Meteorology's climate data, hot on the heels of an LNP Senate candidate doing the same.
"They haven't released the true facts and figures as far as temperature changes over the years. They've fiddled with facts and figures," the One Nation leader said.
Gerard Rennick, who is in the Queensland LNP's winnable third position, last month accused the weather bureau of rewriting weather records to fit in with the "global warming agenda".
"Our public servants are out of control," he said on Facebook.
Labor's campaign spokesman Jim Chalmers says both parties are being poisoned by "crackpot stuff".
"That's very concerning to hear the LNP dance to One Nation's tune on issues like climate change, which the Australian people want a sensible and responsible plan to deal with," he told reporters in Canberra on Tuesday.
"It's a reminder that it's very hard to tell where One Nation ends and the LNP begins."
The bureau has strongly rejected the allegations, pointing to the nation's leading statisticians and mathematicians' support for their methods.