Prime Minister Tony Abbott signalled the government was thinking this way last year when, amid criticism of Australia's approach during the Lima climate conference last December, he described the national bipartisan target - a minimum 5 per cent below 2000 levels by 2020 – as a 12 per cent cut. Illustration: Matt Golding. A government press release on Saturday adjusted that to describing the target as "equivalent to a reduction of 13 per cent below 2005 levels" and did not mention 5 per cent. Climate analysts said adopting a different baseline year for post-2020 targets in a planned global climate deal would be no problem if it came with an ambitious target comparable to other Western countries. But they said it would be condemned at international negotiations if it was seen to be "cooking the books" – using an accounting trick to make a low number seem slightly better.

Climate Institute deputy chief executive Erwin Jackson said Australia was one of the world's biggest emitters in per capita terms, and had a history of expecting the rest of the world to subsidise its emissions. "The key test for the government is not whether it uses 1990, 2000 or 2005 - it is whether it is doing Australia's fair bit to avoid irreversible and dangerous climate impact on Australia," he said. There is no agreed baseline for climate targets at UN talks. The argument in favour of Australia moving to 2005 is that is the year the US, Japan and Canada uses. President Barack Obama last year announced a target of a cut of between 26 and 28 per cent below 2005 levels by 2025.The US is due to formally submit its target to the UN this week. Emissions in the US fell between 2000 and 2005, meaning its target would be a larger number if it used the earlier year. Experts say the key test of a post-2020 target is less the total number - which can be manipulated by whichever baseline year is chosen - than whether a country is significantly accelerating the pace at which it is cutting emissions.

An issues paper on climate targets released on Saturday sets the groundwork for the government to argue it deserves special treatment at the UN negotiations on the grounds it is more reliant than others on resource and agricultural industries. Environment Minister Greg Hunt said: "We are committed to action on climate change because it's real and significant and important. "We are one of the few countries in the world to have met and beaten our first round of Kyoto targets and to be on target to meet and beat our second round of Kyoto targets." The Greens said the paper put Australia on track for a repeat of negotiations on the 1997 Kyoto Protocol, when Australia argued it should be made an exception because of the economy's high dependence on coal. The Climate Institute said the paper used a scenario that would put the world on track for nearly 4 degrees of warming, far more than the globally agreed goal of 2 degrees.

Economist Frank Jotzo, from the Crawford School of Public Policy at ANU, said he supported moving to a 2005 base, but that Australia needed to follow the US and European Union in ramping up the pace at which it planned to cut emissions next decade. Australia's current target requires cutting emissions by 0.8 per cent each year. After 2020, the US target means a cut of 2.5 per cent a year. The European Union target is equivalent of a 2.8 per cent annual cut. Professor Jotzo said Australia was expected to at least be matching this pace, and probably to be doing more. "Australia's 5 per cent target for 2020 is seen as inadequate internationally," Professor Jotzo said. "It is a much weaker target than the US target and it turns out, based on data that the government has just posted, that it is very easy to achieve it. On top of that, our per capita emissions are much higher than all other developed countries." The federal Climate Change Authority last year recommended Australia adopt a 2025 target that would be equivalent to a 40 per cent cut below 2005 levels.

Australia currently does not have a climate policy beyond 2020. Analysts have suggested its "direct action" policy – largely, a $2.55 billion taxpayer fund to pay polluters and farmers to cut emissions – is unlikely to meet the 2020 target. The Australia has signalled it would announce its post-2020 target by mid-year, after most other countries. Labor has accused the government of not being serious about tackling climate change, but has not committed to a target beyond the minimum 5 per cent cut by 2020. Targets already announced include the EU, which promised a 40 per cent cut below 1990 levels by 2030. China, an emerging economy that has traditionally been treated differently to western nations, but now the world's biggest polluter, has indicated its emissions will stop rising and start to fall by 2030. It is yet to formalise this in a commitment to the UN.