America's top diplomat in Australia has warned the Morrison government that its commitments to cut emissions "will be noticed" by the United States, Europe and China, as the Coalition continues to wrangle over climate policy in the lead-up to the Glasgow climate conference.

Charge d'affaires Mike Goldman also said that while a net zero 2050 target was "necessary" it was "perhaps not sufficient" to stave off the climate crisis without sharper cuts to pollution this decade.

It comes as the Biden administration tries to increase pressure on major emitters to ramp up their climate commitments in the lead up to the Glasgow summit.

Net zero target 'necessary'

Prime Minister Scott Morrison and top Liberals are still trying to win agreement from the Nationals for the federal government to formally embrace a net zero by 2050 target that the Prime Minister can take to Glasgow.

The junior Coalition partner has also made it clear it will not back any increase to Australia's current short-term target to cut emissions by 26 per cent to 28 per cent by 2030.

But this morning Mr Goldman told a climate conference that "there has to be ambition" to make deeper cuts to emissions by 2030 in order to make the 2050 target meaningful.

"[Net zero by] 2050 is necessary [but] perhaps it's not sufficient. You won't magically in 2049 decide OK we are going to shut everything off and you'll get to net zero within a year," he said.

"There needs to be all sorts of preliminary steps and these preliminary steps are better undertaken in the early years in this decade, than in the 2040s. So, in that sense we are looking for increased ambition.

Mr Goldman said that the Paris climate agreement was clear that all countries should re-evaluate their position and make new climate commitments for this decade.

He also observed that Australia's carbon emissions were not insignificant.

"Australia isn't in aggregate as big an emitter as China or the United States, or even close, but according to the Union of Concerned Scientists it comes in at number 16 globally, so in the top 20," he said.

Australia has an 'important role' at Glasgow 

The charge d'affaires also said that Australia had an "important role" to play at Glasgow because it was one of the top emitters in the world on a per capita basis.

That meant it had a "similar level of responsibility" as the US to cut emissions, and the US pledged to reduce greenhouse gas pollution by 50 to 52 per cent by 2030.

"Moreover, as a G20 partner and a democracy and as one of the world's most advanced economies, Australia's positions will be noticed," Mr Goldman said.

"It will be noticed by us, Australia's positions will be noticed in Europe, by our partners, and by leaders in Beijing."

He also praised a recent speech from federal Treasurer Josh Frydenberg, who warned last month that investors might abandon Australia if it lagged on climate action.

"There are clear costs to inaction. The IPCC laid out environment costs in terms that are stark and undeniable, but there are economic costs as well," he said.

Foreign pressure ramping up 

European countries have also been applying pressure on Australia to increase its commitments to cut emissions this decade.

Yesterday evening, French ambassador to Australia Jean-Pierre Thebault lavished praise on state governments and the private sector for their climate commitments, while pointedly excluding the federal government.

"Australia has the ability to be a strong voice in Glasgow and can announce the strong commitments that are needed and expected by all stakeholders," Mr Thebault said.

UK High Commissioner Vicki Treadell also said that all countries needed to make more ambitious commitments to cutting emissions at Glasgow, although she said she didn't want to be drawn into Australia's domestic debate on climate policy.