Rich-poor stoush flares in Paris
An Australian campaign to get other nations to accept its definition of carbon dioxide emissions is hanging in the balance, raising doubts over whether Prime Minister Malcolm Turnbull can easily deliver the 5 per cent cut in emissions his government has promised.
At stake is whether Australia will be deemed by the United Nations to be on course to reach its goal of cutting emissions by 5 per cent by 2020 (compared with 2000) - as the government says will comfortably be achieved - or whether they are actually calculated to be rising. 
If it is the latter, it would require a big shift in Australia's emissions trajectory in just five years to meet the target.
As reported by Fairfax Media, Australia has met resistance during the Paris climate summit to including deforestation in the definition of emissions covered to 2020. Including deforestation allows Australia to meet pollution goals even as emissions from industrial and other sources rise.
Extended talks late into Thursday night in Paris were yet to reach an agreement on the definition. If unresolved tonight, it is understood that the problem could be been kicked on to a meeting in   June next year - well after Paris is supposed to deliver a global post-2020 by   December 11.
A postponement would pose a potential embarrassment for the Turnbull government after the PM on Monday told more than 150 world leaders Australia would ratify the second phase of the Kyoto Protocol, a legally binding treaty to cut emissions.
Mr Turnbull's speech, which drew applause from delegates, raised eyebrows among diplomats who knew that the emissions accounting language had yet to be resolved.
The impact of an unfavourable definition, were Australia to accept it, would be in the order of 60-120 million tonnes. By comparison, the government's $2.55 billion Emissions Reduction Fund has spent almost half its money paying for 92 million tonnes of abatement.
Fairfax Media sought comment from Environment Minister Greg Hunt on whether he stuck by comments made a day earlier that he was "fully confident that the rules will remain as they are and accommodate all of our objectives", and the government would ratify Kyoto.
One delegate described how the team was being put under "enormous pressure" by Australian negotiators. The delegate also noted such talks are typically held by technical experts, but the Australian party had lawyers trying to press acceptance of their definition of emissions.
'An accident'
It's understood the problem for Australia stemmed from text added to the Doha Amendment to the Kyoto Protocol, agreed by parties in the Qatari capital in 2012. The implication of the changes did not dawn on parties for some months afterwards.
"At its heart, it looks like an accident," the negotiator said.
Accident or not, Australian governments have relied on variations of the "Australia clause" that allowed the country to take credit for slowing land clearing - particularly in Queensland and NSW.
Instead of trending towards the national target of cutting 2000-levels emissions five per cent by 2020, the outcome should land use changes be excluded would be about an 11 per cent increase, analysts at the University of Melbourne say.
Not so easy targets
"I think it sounds like an admission that Australia might not meet its commitments of a 5 per cent (cut)," Larissa Waters, deputy Greens leader, said in Paris.

 "If we haven't actually finalised what the definition [of emissions] is, how does the Minister [Mr Hunt] know that we can meet and beat our targets?," she said, referring to comments made repeatedly in recent weeks by the minister.
The deforestation issue might become a factor for different reason. New data released last weekend by the Queensland government shows that in 2013-14 land clearing was back almost to the rate prior to the introduction on limits in 1999.
"That was the single reason why Australia could meet its Kyoto [stage] 1 commitments," Senator Waters said.
The clearing in 2013-14 contributed 35 million tonnes of carbon dioxide, with just under 300,000 hectares of land cleared. "And that's only one year," Senator Waters said.
Australia's bid to make sure deforestation is included in the definition of emissions, therefore, "could come back to bite Mr Hunt", she said.
Fairfax Media is a partner of United Nations Foundation