When Prime Minister Malcolm Turnbull rose to address the United Nations Climate Change Conference in Paris late last year, he told the world Australia would meet the challenges of global warming "with confidence and optimism".

Australia's carbon emissions target - slicing 2000 levels by about 19 per cent by 2030 - would halve pollution on a per capita basis, "one of the biggest reductions" of any G20 nation, Turnbull said.

The government would also double "clean energy innovation" investment over the next five years, and carve out $1 billion from the existing aid budget to help threatened Pacific neighbours build "climate resilience" and cut emissions.

One cause for optimism was that Australian universities were leading the charge in "energy and climate science innovation".

The University of NSW had held the world record for solar cell efficiency – now at 25.6 per cent – for 30 of the past 32 years.  And by 2018, more than 60 per cent of all new solar cells would use technology developed in Australia, Turnbull noted.

And on Friday, New York time, Environment Minister Greg Hunt will take the next step to lock in the climate pledges when Australia joins more than 150 nations at a UN ceremony to ink the Paris accord.

The pact, which the government plans to ratify later this year if re-elected, aims to limit global temperature increases to between 1.5 and 2 degrees of pre-industrial levels - even if current national offers fall far short of the greenhouse gas reductions needed.

Bad news on the climate front

But in the four months since Turnbull's speech, climate news from abroad and at home has been anything but positive.

Global temperature records were so decisively smashed in the first three months of 2016 that Gavin Schmidt, the head of NASA's Goddard Institute of Space Studies, declared this year is already virtually certain to be the hottest on record – for a third year in a row:

​Hunt's send off wasn't cheery either. Before boarding the plane, he arranged a last-minute teleconference at the behest of Queensland counterpart Steven Miles to address the worst case of coral bleaching to hit the Great Barrier Reef.

During the "occasionally heated" call, Miles says he called for an urgent meeting in Cairns so officials "could witness at first-hand the devastating effects of climate change". Hunt declined the invitation but proposed a weekly ministerial phone call to discuss the unfolding disaster.

"I have been involved in ongoing visits to the Reef and have only recently returned, and will be attending again and for as long as I hold the post," Hunt says, adding that Queensland "could not name one action they would take to actually assist".

But for policy areas directly under Turnbull's control, it's been a dismal few months for climate action, not least CSIRO's assault on climate science launched on February 4 that will see dozens of leading researchers sacked among as many as 450 jobs to go.

Despite pleas of budget penury, the government somehow managed to find $15.4 million a couple of weeks later for a new Oil, Gas and Energy Resources Growth Centre to, among other things, "foster community support" for non-renewables, including coal and nuclear energy.

It is also forked out $3.3 million to two researchers to examine the effects of wind farms on health. Just four researchers made submissions for the cash, a remarkably small number, according to Sydney University public health expert, Simon Chapman.

Taken for granted

And a fresh concern surfaced this week with 61 leading scientists writing to Turnbull decrying the government's decision last month to end grants from the Australian Renewable Energy Agency (ARENA).

Set up by the Rudd-Gillard government, the agency still had $1.3 billion in funding to disperse by 2022.

Instead, it will now work with the Clean Energy Finance Corp to offer $100 million in loans annually for 10 years to foster "clean and renewable energy". ARENA still has $130 million to be allocated, with "high interest" from potential proponents, Hunt says.

The proposed end of ARENA's grant funding removes "an essential component of technology innovation", the mostly solar researchers said in the letter obtained by Fairfax Media.

Forty years of such grants over had allowed Australia to contribute "very far above its weight" in renewable energy. By contrast, reliance on equity returns "have rarely been effective" in advancing early-stage research, the scientists said.

Richard Corkish, chief operating officer of UNSW-based Australian Centre for Advanced Photovoltaics, said his facility faced "an existential threat" if the $4 million in annual ARENA funds ended. The school continues to spawn world-leading technology, including new types of solar cells using abundant, non-toxic materials.

"ARENA is our major funding source," Corkish says.

Andrew Blakers, who led development of the solar PV technology being adopted by the world's largest producers, said all new electricity investment in Australia over the past five years had been in solar or wind energy.

"This is incredible", says Blakers, who heads the Centre for Sustainable Energy Systems at the Australian National University. "You don't turn off R&D spending when there's a revolution under way."

A record $US286 billion ($366 billion) was invested in renewable energy research and deployment last year, the UN Environment Programme said on Thursday. About $US130 billion was spent on new coal and gas-fired power plants.

The PM's office declined to comment on the letter.

Still a 'black sheep'

Hunt does have a positive story to tell in New York about Australia's ambitions in that per capita emissions will drop more than most nations, says Malte Meinshausen, director of the Australian-German Climate & Energy College at Melbourne University.

"But Australia is still going to be the highest in the developed world" at about 15.7 tonnes of CO2 emitted per person by then, Meinshausen says.

However, even those goals - which will leave Australia "a black sheep" vying with Canada as the worst emitter among rich nations - may be out of reach.

"We are still walking in the other direction," Mainshausen says."The big gap is there are no policies on the horizon" to hit the target.

Paying polluters to cut emissions and other existing measures won't get Australia anywhere close. "It has to be an economy-wide price on carbon in one form or another," he says.

'Pressing challenge'

The government, though, is adamant that Australia is pulling its weight.

"We are in a strong position globally," a spokesperson for Hunt says. "We have shown leadership in helping secure 90 billion tonnes of [CO2-equivalent] abatement as co-chair of the Montreal Protocol discussions."

Along with existing policies - which include the third auction for the Emissions Reduction Fund due next week -  the government will focus on reducing vehicle emissions, a National Energy Productivity Plan, and the phase down of potent hydro-fluorocarbons by 85 per cent, the spokesperson says.

Labor, meanwhile, is yet to release its climate policies, although Mark Butler, opposition environment spokesman, says they are just weeks from doing so.

He notes, though, that while Australia is likely to meet its 2020 target to cut 2000-level emissions by 5 per cent, it would do so largely because of surplus credits under the existing Kyoto treaty: "By the government's own figures, by 2020 emissions will be 6 per cent above 2000 levels and will keep on rising."

"The pressing challenge is to get emissions back under control and have them falling in the medium term to 2030."

Greens deputy leader Larissa Waters said there's "an obvious disconnect between the Prime Minster's rhetoric in Paris last year and his actions in Canberra".

"Presiding over cuts to CSIRO's world-leading climate research and gutting renewable technology research is stupid on so many levels.

"The government is tipping new money into fossil fuel research so that the big mining companies profiting off the world's warming don't have to pay for research themselves," Waters says.

Hunt, meanwhile, may be asked in New York about the state of the Great Barrier Reef, an issue the World Meteorological Organisation dubbed one of the "worrying developments" in the sizzling start to 2016.

"The magnitude of the changes has been a surprise even for veteran climate scientists," Petteri Taalas, WMO's secretary-general, said ahead of the UN gathering.

"The state of the planet is changing before our eyes."