The deputy prime minister is demanding to see more detail about the economic impacts of signing up Australia to net zero carbon emissions by 2050 before backing the target.

That's despite a major international climate report card warning the planet is poised to be 1.5C warmer, compared with pre-industrial levels, by early next decade.

The Intergovernmental Panel on Climate Change predicts more frequent and ferocious fires, floods, droughts, and accelerated sea level rise because of human-induced climate change.

Mr Joyce said he understood the emotion, and to some extent the moral argument, around more action.

But the Nationals leader said experts including CSIRO needed to be up front about the cost of climate action.

"You're making an answer to the equation without actually telling the people the numbers that got there," he told ABC radio on Wednesday.

"We don't believe in legislating until we have a clear understanding of exactly where the costs are. Otherwise you just have an open book."

Prime Minister Scott Morrison has flagged Australia will update its 2030 emissions projections at the UN climate change conference in November.

The government wants to achieve net zero emissions as quickly as possible and preferably by mid-century.

But international pressure is rising ahead of the meeting in Glasgow with Australia seen as a global laggard on climate action.

Mr Morrison is sticking to the government's "technology not taxes" manta to insist a global effort can counter the catastrophic effect of a warmer climate.

"Our government is not going to write a blank cheque on this," he told parliament.

"What we will do is consider this carefully and have a clear plan which we can take Australians with us on."

The prime minister accuses the opposition for lacking a path to net zero by 2050 but deputy Labor leader Richard Marles insists a clear plan will be outlined before the next election.

"The most recent report is incredibly concerning reading. If it doesn't shock this government into action, nothing will," Mr Marles told ABC radio.

Independent MP Helen Haines, who represents a rural electorate in northeast Victoria, has urged the government to commit to net zero emissions by 2050.

"Regional communities are already carrying this burden - drought, bushfires, floods and future trade costs," she told parliament.

More than 130 countries along with major multinational companies including financial institutions have backed a net zero 2050 target.

Australian Associated Press