Treasurer Wayne Swan and Climate Change Minister Penny Wong issued Treasury's ''hard-headed assessment'' of the economic impact of an emissions trading scheme yesterday.

Opposition Leader Malcolm Turnbull said the modelling indicated the Government must exercise ''great care''.

''We have already seen the consequences of one rushed and bungled economic policy decision made by the Rudd Government. We can't afford to have a second.''

But Greens climate change spokeswoman Senator Christine Milne said figures backed their position that ''hard and fast'' cuts to emissions would make economic and environmental sense.

''The modelling shows that the Government has no excuse whatsoever for refusing to take on at least 25 per cent cuts by 2020,'' she said.

''Treasury should now be asked to model the 40 per cent cuts we know are necessary in order to pass on a safe climate to our children.''

Australian Industry Group chief executive Heather Ridout urged the Government to take a cautious approach to emissions trading.

''The modelling points to very substantial adjustments ahead for the Australian economy and it serves to highlight the potentially damaging impacts on businesses and employees of moving too fast and too far ahead of the rest of the world.''

The Climate Institute's director of policy and research, Erwin Jackson, said the figures showed the country could tackle ''dangerous climate change'' and still have growth.

''Treasury has set the scene for the Government to adopt strong, credible 2020 pollution reduction targets and position Australia to tap into the emerging trillion-dollar low-carbon global economy,'' he said.

''Treasury modelling has [also] now discredited the irresponsible claims by some of the big polluters, undermining suggestions that early, strong action should be delayed.''