The Rudd Government's target to cut Australia's greenhouse emissions by 60 per cent by 2050 sets the bar too low to avoid dangerous climate change, a new report says.

''The science has moved on. We need to pursue a more aggressive mitigation strategy,'' the report's principal author, Australian National University Climate Law and Policy Institute co-director Andrew Macintosh said.

In a study to be issued today Mr Macintosh says new climate models show greenhouse emissions cuts required to prevent the global average temperatures increasing by more than 2to3degrees above pre-industrial levels are far greater than previously believed.

''A 60 per cent mitigation target for developed countries for 2050 is likely to fall well short of what is required if there is a desire to keep the temperature increase below 3degrees.''

Mr Macintosh said the Rudd Government's current mitigation target appeared to be based on Intergovernmental Panel on Climate Change figures ''dating from the 1990s'' because of the time lag in collating scientific data for the panel's reports.

''We have to leapfrog those figures and enter a new realm. Australia would need to set interim goals to reduce emissions by 30percent by 2020, and aim to move toward 70 per cent by 2030,'' he said.

Federal Government climate change policy-makers were also ignoring new data on the declining ability of the Earth's oceans and forests to absorb carbon dioxide.

''If the uptake and storage of carbon by natural sinks declines, a greater proportion of carbon emissions will remain in the atmosphere. That's known as the airborne fraction.

''As a result, meeting climate targets based on atmospheric concentration of carbon dioxide will be more difficult, requiring a greater reduction in emissions than would otherwise be necessary.''

The interaction between temperature change, atmospheric carbon dioxide levels and the natural cycle by which carbon is exchanged between land, oceans and atmosphere is known as the climate-carbon cycle feedback.

Mr Macintosh said the importance of this cycle feedback was well known to scientists, but tended to be overlooked or ignored by those drafting climate change policy. This policy oversight and the ''massive time lag'' in scientific data being assessed for inclusion in IPCC reports could result in greenhouse abatement targets being set too low by developing countries.

According to the ''best guess'' of the panel, stabilisation of the atmospheric concentration of greenhouse gases at 550 parts per million would lead to warming of around 2.9 degrees, and stabilisation at 650 parts per million is expected to lead to warming of about 3.6 degrees.

Mr Macintosh said after calculating 21st-century national emissions budgets and trajectories to determine levels of abatement necessary to stay within those budgets, results suggested ''without a rapid and dramatic shift in the political landscape'' there was little chance of stabilising atmospheric concentration of carbon dioxide at 450 parts per million.

''It follows that there is little chance of keeping the increase in the global average surface temperature below 2 degrees a level that's been identified as the threshold for dangerous climate change.''