But the treasurer of the most populous New South Wales state, Michael Costa, accused Garnaut of delivering a "Chicken Little" report predicting the sky could fall in on the economy and iconic tourist lures such as the Great Barrier Reef.

"We don't need Chicken Little, we need details," Costa, a left-of-centre lawmaker, said.

"I think it's absurd ... to argue we should dismiss legitimate concerns about the details with broad-based and fairly generalised references to the future of the Great Barrier Reef."

The Garnaut report, which called for a two-year phase-in of the world's most comprehensive emissions trading scheme from 2010, will be matched by a government options paper on how the market might function, to be delivered later this month.

Voters, though, are already fretting over higher petrol and electricity prices the regime will inevitably bring, piling pressure on Prime Minister Kevin Rudd to limit its impact on ordinary Australians.

POLL

A Newspoll in the Australian newspaper on Monday showed support for the government was at the lowest level since last year's November election, with support slipping 4 percentage points to 55 percent, while backing for conservative rivals rose by the same margin to 45 percent.

Rudd's personal approval also plummeted 5 points to 54 percent, while his conservative rival was stable on 36 percent.

Labor's Climate Change Minister and troubleshooter Penny Wong, who will shortly travel to Japan for a meeting of climate ministers from rich nations, said the government could delay the introduction of the emissions scheme to beyond 2010.

"That's the ambition, we said that before the election, we recognise we have to get moving on this. Obviously we'll listen to what people have to say, but that remains the ambition," Wong told local radio.

Australia relies on coal to generate about 77 percent of the country's electricity and is the world's biggest coal exporter, in part accounting for its position as the world's top per head emitter of greenhouse gases.

Rudd has promised to combat climate change and deliver a 60 percent reduction in greenhouse gases by 2050 as climate scientists warn the country, already the world's driest inhabited continent, is suffering accelerated climate shift.

A government report on Sunday said Australia could experience drought twice as frequently in the next 20 to 30 years, shredding agricultural production and threatening the country's place as the world's second biggest wheat exporter.

Industry critics have warned Rudd the 2010 emissions trade target may be too ambitious, while backing free permits for big polluting emitters such as electricity generators rather than a competitive auctions tipped to net up to US$19 billion.

Power generators say they will have to raise prices, while farmers and coal-miners warn of lost overseas competitiveness under emissions trading, which allow corporates to buy and sell permits to emit greenhouse gases. (Editing by Alex Richardson)