Family First Senator Steve Fielding says increasing levels of carbon dioxide in the atmosphere might not be causing global warming.
He has been at a climate change conference in the United States where he heard that solar flares could be linked to temperature change. The Government wants the Senate to vote on its carbon reduction scheme this month.
Senator Fielding says he wants to talk to government scientists about his concerns before he will be able to vote on the scheme. "The issue that has been put forward is that over the last decade carbon emissions have been going up but global temperature hasn't," he said.
"Now that puts the question - is carbon emissions really the major driving force of global temperature change? And what I heard at the conference is that solar activity seems to be more closely aligned to global temperature changes over a long period of time.
"Now obviously that's a question mark that I need to get to the bottom. Now I'm an engineer, so I suppose that when someone puts forward an opposing view, I've got to check out to make sure whether it's right or wrong."
Senator Fielding says he wants to take the information he has and give it to government scientists.
"If the answer is, 'Look, it's just rubbish' and they're just going to discount it, well I think that's not good enough," he said.
"I think you need to argue a case on a scientific basis.
"Because this is a huge issue, that if we get it wrong, it's going to actually end up costing Australia very, very dearly, and I think we need to get to the bottom of it."
He says people have just accepted what they have been told about carbon emissions, but credible scientists have put forward alternative views.
"We need to actually take that information to scientists that believe differently and have them argue back, rather than just discounting it out of hand," he said.
"I'm not saying I believe that yet, but it's certainly... it seems to have merit, there seems to be some credibility in it, and I need to resolve that for myself, but I think all of Australia needs to have that answered as well."
Senator Fielding says he will discuss the issue with Climate Change Minister Penny Wong when he meets with her this week.
"I intend to take some of the graphs and the charts that I've actually got from Tuesday, and ask her to explain why what they've put forward isn't credible," he said.
"And the big question that I've got: what happens if what they're saying is true, and we're actually going to actually be addressing climate change with reducing carbon emissions; in effect, that may not do what we want it to do."
He says he may be able to vote on the issue within the Government's timeframe of the end of June - if he gets access to government scientists.
"If the Government's fair dinkum they'll give me access to their scientists, and we'll be able to have decent and open discussions on a scientific basis looking at the stuff that I've got that I can give them, and that way we can hopefully get to the bottom of it," he said.
"But it's up to the Government; if the Government give me access to their scientists, and we have a decent, open debate, then I think we can."