This target would be a minimum requirement for Australia's contribution to an effective global climate agreement that would aim to limit atmospheric carbon dioxide levels to an equivalent concentration of no more than 450 parts per million.
"Failure of the world to act now will leave Australians with a legacy of economic, environmental, social and health costs that will dwarf the scale of national investment required to address this fundamental problem," says the letter signed by leading researchers from the nation's top university and research institutions. "There is no time to lose."
The letter to Kevin Rudd comes on the eve of the final report by the Government's climate change adviser, Professor Ross Garnaut, and presents a challenge to one of his key findings.
Earlier this month, Professor Garnaut advised the Prime Minister to make a slower start to cutting emissions, recommending Australia reduce its greenhouse gases by 10% by 2020.
The letter's signatories say that the urgent goal now is to limit global warming to no more than 2