New One Nation senator-elect Malcolm Roberts has argued the United Nations is trying to impose global government through climate change policy.

He has also called for a section of the Racial Discrimination Act to be repealed so the nation can have a proper discussion about tax, Islam and the economy.

Key points: Coalition will rely on 11 crossbenchers for votes to pass legislation

Coalition will rely on 11 crossbenchers for votes to pass legislation One Nation's Malcolm Roberts is a prominent climate change sceptic with the Galileo Movement

One Nation's Malcolm Roberts is a prominent climate change sceptic with the Galileo Movement He says his allegiance is to Queenslanders, not Ms Hanson

Mr Roberts is one of three One Nation senators joining party leader Pauline Hanson in the new-look Upper House, after the final vote count was finalised today.

In an interview on ABC local radio, Mr Roberts said there were a number of movements undermining Australian sovereignty.

"Do you think the UN's trying to impose some sort of global government through climate change policy?" 774 ABC Melbourne host Rafael Epstein asked.

"Definitely," replied Mr Roberts.

Along with his concerns about climate science, Mr Roberts argued that discussion on the big issues facing the country was being squashed.

"We need people to speak up freely and deliver what they really believe and yet they get slammed for that," Mr Roberts told reporters in Brisbane.

"I'm looking at [section] 18C under the Racial Discrimination Act — that needs to be addressed because that is curbing free speech.

"When we have free speech curbed, it means we don't talk about the real issues — tax, Islam, terrorism, the economy."

Attorney-General George Brandis said he was not considering repealing 18C.

Responding to Senator Roberts' comments, Senator Brandis told ABC's 7.30: "The Government's position remains as it has been since September 2014; that issue is off the table."

Former prime minister Tony Abbott dumped plans to change the meaning of section 18C of the Racial Discrimination Act in 2014, saying they had become a "complication" in the Government's relationship with the Muslim community.

Section 18C makes it illegal to carry out an act if "(a) the act is reasonably likely, in all the circumstances, to offend, insult, humiliate or intimidate another person or a group of people; and (b) the act is done because of the race, colour or national or ethnic origin of the other person or of some or all of the people in the group".

Addressing the media without Ms Hanson, Mr Roberts said his allegiance was to the people of Queensland, not his party leader.

He said he had already spoken with Prime Minister Malcolm Turnbull and Senator Brandis, who he assured of his dedication to his home state.

"Although I have enormous respect for Pauline Hanson, and I really do, my number one allegiance is to the people of Queensland and Australia," he said.

"That is what a senator is responsible for."

United Nations 'driving' climate science

Mr Roberts, a prominent climate change sceptic with the Galileo Movement, also renewed calls for an inquiry into CSIRO's climate change research.

Mr Roberts, whose latest press release stated that he "spent the last nine years working pro bono checking alarmist climate claims", said he wanted to repeal any legislation put in place "as a result of the claim that humans affect global climate as a result of our use of hydrocarbons fuels, coal, oil, natural gas".

Describing himself as a scientist, he said "we need to stop these ridiculous lies based on climate".

"I went looking into the agencies that have been spreading the climate science," he said.

"I started finding out things about the CSIRO and Bureau of Meteorology.

"That led me then to the UN, which has been driving this.

"Then I started following the money trails. It's important to understand the motives."

Final count puts 11 crossbenchers in Senate

The final Senate vote count was revealed on Thursday, with Mr Turnbull now facing the task of negotiating with 11 crossbench senators.

The Coalition has lost three seats in the Upper House, returning with 30 senators, while the ALP has gained one senate seat, taking its tally to 26.

The Government needs 39 votes to pass legislation, leaving it to negotiate with the crossbench — up from eight to 11 — comprised of four One Nation senators, three Nick Xenophon Team senators, as well as independents such as Jacqui Lambie and Derryn Hinch.

Family First senator Bob Day and Liberal Democrat David Leyonhjelm were also returned, as well as nine Greens (down from 10 in the previous government).

One Nation polled more than 9 per cent of the first-preference vote in Queensland, securing up to 21 per cent in the conservative South Queensland seat of Wright.

Its other two senators will be Brian Burston in New South Wales and Rod Culleton in WA.

Opposition Leader Bill Shorten attributed Ms Hanson's success to Mr Turnbull and Greens leader Richard Di Natale.

Speaking to media in Sydney, Mr Shorten said the election of Ms Hanson and her colleagues was a result of voting reform and a double dissolution.

"The presence in such numbers of One Nation in the Senate is a direct result of Mr Turnbull and Mr Di Natale's action in terms of their so-called electoral reform," he said.