Federal Environment Minister Ian Campbell has admitted Australia risks going over its greenhouse emissions target.
The minister's concession followed a question from Australian Greens senator Christine Milne.
Australia's greenhouse gas emissions were set at 108 per cent of its 1990 levels.
Senator Campbell said while tracking shows the target could still be met, factors could change it.
"The fact is that because of the very strong growth in our economy there is certainly a risk in going over the 108, we may in fact do that," Senator Campbell said.
"I am flagging the potential that we could go over, we could go over."
The minister said if the target is not met then measures could be put in place to remedy the problem.
However he ruled out the introduction of emission trading and a carbon tax.
"If I thought emissions trading would solve Australia's problem we would do it but it won't. All it does is put a new tax on the economy," he said.
Senator Milne said there needed to be a better explanation of why the target is in danger.
"Minister Campbell's admission that Australia may not meet its greenhouse gas reduction target under the Kyoto Protocol stands in stark contrast to the confident claims he and Prime Minister John Howard have made for years that Australia is one of few countries that will meet its target," she said in a later statement.
Australia has continued to refuse to sign the Kyoto protocol.
Labor's environment spokesman Anthony Albanese said Senator Campbell's admission showed the flaws in the Howard government's climate policy.
"The Howard government is not taking climate change seriously, placing our economy and environment at serious risk," Mr Albanese said.