During estimates on Thursday, the Department of Industry, Science, Energy and Resources unveiled the modelling which has been kept secret due to "cabinet in confidence" had not yet been completed for public publication.

Prime Minister Scott Morrison has pledged the modelling would be made public in the next few weeks, a move which has enraged Labor throughout the estimates week.

The political tit-for-tat between the major parties reached a boiling point on Thursday afternoon, after a fiery exchange was thrown down been Liberal senator Zed Seselja and Labor senator Murray Watt.

Senator Watt launched into Senator Seselja, calling him "such a fraud" over the federal government's net zero stance.

Watt attempted to trip up the ACT senator over comments he made in 2020, saying a 2050 target would be "reckless".

"You are so embarrassed ... Why are you such a fraud?" Senator Watt shouted.

Chair Paul Scarr interjected saying the hearing was "descending into farce".

Senator Seselja argued Labor put down an idea with absolutely no plan.

"The Labor party put forward an idea without [knowing] how to get there. That is absolutely reckless," he said.

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Senator Seselja said Queenslanders "saw through you" at the last election, evidenced by Labor's 22 per cent Senate primary vote in the state.

DISER deputy secretary Jo Evans said the modelling provided to the Morrison government for its climate change pledge ahead of the Glasgow summits, is not yet suitable for publication.

Ms Evans said the modelling is complete and that the department is finalising its public report.

Labor senator Jenny McAllister argued the federal government's secrecy of the modeling has blocked public and business consultation.

"Why does this all have to be in secret," Senator McAllister said.

"Why are these things being concluded, wrapped up and Mr Morrison is off to Glasgow before you are willing to show the public your workings. What is there to hide?"

Senator Allister also probed DISER secretary David Fredericks in what form the modelling was provided to cabinet, given the department had stated it was not ready for public consumption.

Mr Fredericks replied: "I can't talk to that. The best I can say to you is that of course, the modeling was available to the cabinet in accordance with cabinet processes".

DISER also revealed the modelling conducted by McKinsey cost upward of $6 million in contracts.

Ms Evans said the consulting group received $4.8 million and $1.2 million, for two separate contracts which were based on a 2 degree celsius model and its impact to the economy.

The net zero report put out by the government on Tuesday shows Australian fossil fuel exports by 2050 are expected to decline by 35 per cent on 2020 levels.

In a question posed by Liberal senator Sam McMahon, Ms Evans said the job losses and industry impacts would be felt in heavy resource communities such as Gladstone and Newcastle.

In question time, Labor honed in on the net zero plan, with Opposition Leader Anthony Albanese claiming Mr Morrison attacked be emission targets before he had adopted them.

"Why should Australians trust a government with net-zero credibility on Australia's clean energy future?," he said.

Mr Morrison responded by saying he opposed Labor's targets which would have destroyed industries.