Australia has agreed to strongly support a push to include a 1.5-degree global warming goal in a Paris agreement in exchange for more favourable carbon emissions rules.

St Lucia Environment Minister James Fletcher revealed the deal, which also involves South Africa, in Paris on Saturday at major climate talks, which aim to produce an agreement to curb global warming.

It does not mean Australia has changed its stance from aiming for two degrees, but that negotiators would support the 1.5 being mentioned as a looser ambition in the Paris document.

It's understood the deal was brokered in Paris, although that has been Australia's position since before the talks.

The trio of nations had long been at loggerheads over the definition of carbon emissions under the Kyoto Protocol, under which Australia's 2020 reduction target of five per cent is set.

The deal means countries, including Australia, can use land use sector emissions, such as deforestation reduction, in accounting rules for Kyoto.

In exchange, Australia agreed to play a brokering role to help St Lucia convince other nations to support the inclusion of a 1.5-degree ambition in the Paris deal.

The two-degree target is accepted by most major economies, including the United States.
Environment Minister Greg Hunt said Australia had held "very constructive" conversations with St Lucia and other countries on Kyoto and a final Paris agreement.

Australia had already raised a request that a 1.5-degree trajectory be modelled by the UN climate science body, a spokesman told AAP.

Dr Fletcher said he believed the trio had a "very clear" set of rules that would allow counties to "examine exactly what Australia is doing" under Kyoto.

"We devised a way in ensuring there is clear transparent accounting in how Australia deals with those credits that it's carrying over from the last period," Dr Fletcher told reporters in Paris.

The Kyoto rules were agreed to in a meeting on Friday night and will be officially signed off next week.

The revelation of a deal comes after Denmark, Germany, the Netherlands, Sweden and the United Kingdom jointly announced on Friday they would abandon carry-over credits under Kyoto.

Under the protocol, excess emissions reductions achieved in the first period can be carried over to the second, something Mr Hunt is relying on.

The collection of European countries hope abandoning those credits will show the globe they're willing to act on climate change.

"By cancelling surplus units we hope to send a strong positive signal of support for an ambitious global climate agreement here in Paris," they said in a statement.