A plan to make Australia a net zero carbon emitter by 2050 remains in Labor's sights, with Opposition leader Anthony Albanese adopting the policy his predecessor took to the last election.

Key points: Labor has been reviewing all of its climate policy targets since its shock defeat at last year's election

Labor has been reviewing all of its climate policy targets since its shock defeat at last year's election There has been angst within Labor ranks over emissions targets and the future of coal

There has been angst within Labor ranks over emissions targets and the future of coal A policy expert says it would require some big changes to reach net zero emissions by 2050

All of Labor's policies have been up for review since its shock election loss last May.

But in a sign the party is beginning to lock in policies it will take to the next election, Mr Albanese will recommit his party to the 2050 commitment in a speech in Melbourne.

It remains unclear, however, what emission target Labor will seek to achieve by 2030.

While announcing the 2050 goal, Mr Albanese will not outline how Labor will achieve it, a move the party's climate change spokesman defended.

"We're a quarter of the way through a parliamentary term in Opposition," Mark Butler said.

"There is a process of developing policy. You start with core principles, you then start talking to organisations like the [Business Council of Australia] and the so many other businesses and stakeholder groups about the details so that well before the election there is a detailed policy that we as the alternative government can put before the Australian people."

The Government is yet to make up its mind on whether to back a net zero 2050 target.

Labor's 2030 goal remains unclear

Labor was criticised at the last election for not being able to explain how much its climate policies would cost.

If it had won the election, the party planned to cut emissions by 45 per cent, based on 2005 levels, by 2030.

Mr Butler said more work was needed before the party settled on a 2030 target.

"We are going to have to take advice about what a proper, responsible, medium-term target to release in 2022 is going to be," he said.

"But I make this commitment, it will be consistent with the pathways set out in the Paris climate agreement, consistent with net zero emissions by the middle of the century."

Energy Minister Angus Taylor said locking in the 2050 target was no substitute for not announcing a shorter-term goal.

"It's absolutely crucial we focus on getting outcomes for 2030, that's where we're focused, and it's also crucial that any target that's set has a clear plan to get there and is properly costed," Mr Taylor told AM.

Labor's plan is also facing criticism from the Greens, with new leader Adam Bandt arguing the Opposition needed to lock in a short-term goal before adopting a long-term target.

"If all we do is head to zero by 2050 starting from the next election, we will blow our Paris two-degrees budget," he said.

"We need strong 2030 targets. Labor, by ditching its 2030 targets and instead focusing on a 2050 — that blows the Paris agreement — is letting Scott Morrison off the hook, because now there'll be less pressure on him to take action by 2030."

What does net zero by 2050 look like?

2050 seems a long way off.

But Australia would need to make some big changes to get to net zero emissions by then, according to Ben Oquist from policy thinktank The Australia Institute.

There has been angst within Labor ranks over the future of coal. ( Reuters: Jason Lee )

"Electricity will still be electricity, and it'll arrive into your TV screen in the same way, but it'll be produced by renewable resources," Mr Oquist said.

"Cars will be electric and will be charged up using renewable energy resources."

State governments have backed the 2050 target, as have big business groups.

And Mr Oquist says it would see Australia balance the emissions it puts into the atmosphere with those it takes out.

"Net is important," he said.

"Some sections of the economy, it's more easy to get to zero emissions — like the electricity sector. Technology's already in place through renewables and storage, that means cheaper electricity can be produced with zero emissions.

"Other sectors of the economy are harder to get to zero — agriculture for example.

"But some sections of our society can store carbon. You can store carbon in the landscape, in the trees, in bushland."