THE federal opposition hasn't ruled out putting a price on carbon for emissions trading if the United States were to adopt a similar scheme. 

Opposition climate spokesman Greg Hunt says the coalition's approach to tackling climate change is flexible, and targets are adjustable should global agreements be made.

Asked if the opposition would follow suit should the US implement a carbon price, Mr Hunt said: "Our system is flexible."

But he said the globe was moving away from such systems.

"The history to come is going to the opposition direction," he told ABC television on Thursday.

"It's very clear that the United States is moving away from the sort of system that (Prime Minister Kevin) Rudd is proposing."

The opposition's direct action plan - as opposed to the cap-and-trade scheme proposed by the federal government - was in fact "identifying the direction of history", Mr Hunt said.

He defended the policy following criticisms from one of Australia's top climate experts, Professor Ross Garnaut, who likened it to communist schemes of the old Soviet Union.

Professor Garnaut "took a swipe at both sides", Mr Hunt said. The government's top climate adviser had also bagged as an abomination the amount of compensation it planned to pay to polluters.

Meanwhile, media reports indicate the Governemtn will delay reintroducing its emmissions trading scheme in parliament, prompting Opposition accusations that it is on the verge of a backlfip over the scheme.

The legislation was expected to be reintroduced into parliament last week.