As the Senate prepares to vote on Bills to establish an emissions trading scheme, about 200 protesters converged on Parliament to demand deeper cuts to emissions.

They blocked the public entrance for a few hours, brandishing signs stating ''Rudd the world is watching make Copenhagen count'', ''Failure is not an option'', ''Rudd is betraying us'' and ''Mr Rudd listen to the people not the polluters''.

At one point, Family First Senator Steve Fielding emerged from the building with his own poster a laminated copy of a graph labelled an ''Inconvenient fact''.

Senator Fielding argued the graph showed global temperatures had not increased in line with rising carbon emissions in the past 15 years.

Zero Emissions Now spokesman Matthew Wright took the senator to task, saying the father-of-three should show more concern for the future of the planet and visit the Australian National University to listen to real climate change scientists.

''I'm sorry Steve. You can try and manufacture that shit around here and get yourself some media, but no one's going to believe it,'' Mr Wright said, attracting cheers.

It was the first act of ''civil disobedience'' by Jenny Curtis, who delivered the protesters' message.

''Prime Minister [Kevin] Rudd has the capacity to be a world leader,'' Ms Curtis said in the lead-up to global climate talks in Copenhagen.

''He has the capacity to influence the US. If he goes to Copenhagen with a 40 per cent target then he has the capacity to shift things globally.''

At 12.30pm, police directed the protesters to leave and gave them 15 minutes to comply.

More than 20 police officers moved in at about 1pm and forcibly removed the protesters one-by-one, taking some to the underground car park where paddy wagons were waiting.

ACT Police reported 101 people were taken into custody.

Parliament House's public entrance was reopened about 3pm about four hours after the protest started.

Demonstration spokeswoman Georgina Woods said the participants had protested on ''behalf of every Australian whose children and grandchildren will be affected by the devastation of climate change''. ''We're here to issue a moral challenge to Rudd to demonstrate true climate leadership at Copenhagen. While he says a legally binding climate treaty is important, the commitments he has put on the table are drastically weakening the deal.''