"If they really believe the science, you wouldn't do a 5 [per cent cut in greenhouse gas emissions], you wouldn't do 20, you would do 30 or 40. If you really believe the science, how could you support anything other than 40 per cent?"

No, the Family First senator hasn't changed his mind on global warming. When The Age found him he had just landed at the Bella Centre, Copenhagen, and was standing in his pinstripe suit in the middle of the atrium, taking in the spectacle of 15,000 people brought together by climate change.

He is among them, but not with them, doubting the science underpinning the conference. He doubts the Government's solution of an emissions trading scheme - a proposal he has helped vote down twice - and doubts the Government is being fair dinkum about its commitment.

He also doubts how he got into the conference: his registration card says he is a member of hardline American sceptics group the Committee for a Constructive Tomorrow. "I don't know about them in detail, and I can say I don't know their policies, so don't tag me with them," he said.

He later called for the summit to be called off while there was an investigation into the validity of climate change science. He used his parliamentary study allowance to pay for the trip.

"Any potential agreement is going to impact any nation significantly," he said. "Given I'm involved in Federal Parliament and my vote does count on issues, it is important you get as close as you can to it."

Senator Fielding is using the visit to spread a few words of his own, having come armed with business card-sized laminates headed "An inconvenient fact?" that he says show the globe has not warmed in 15 years.

He is not convinced by a recent report by the World Meteorological Organisation, based on weather data from 189 countries, that found the 2000s has been the warmest decade on record and that this year is set to be the fifth hottest. "The trouble is it is staying at the same high level and it is not actually going up," he said.

Senator Fielding is one of three federal politicians at the Copenhagen summit. The others are Climate Change Minister Penny Wong and Greens senator Christine Milne. Others will arrive this week. Senator Fielding is critical of the Opposition for not being represented.

"Whether you actually believe they should do more or less, and whether you believe in the science or not, this is a significant conference," he said.