PRIME Minister Kevin Rudd wants to change the world. Opposition leader Brendan Nelson wants to keep Australians running on cheap petrol.

Business worries about costs to their bottom line. The people, with an eye to their children and grandchildren, are with the PM -- until the penny drops, and they waver on Nelson's populist line and the fear put in them by vested industry.

Climate change has got people worked up.

The world sat up just 40 years ago with the convening of the Club of Rome. Then, the concern was that economic growth could not continue indefinitely because of the limited availability of natural resources, particularly oil.

The realisation has become more urgent since, with questions about the very survival of the world as we know it. The argument is how pressing is the problem. How much time do we have? What can be done? At what cost, and who is to pay?
It's a "diabolical" policy problem, as Professor Ross Garnaut, climate change adviser to Australia's federal, state and territory governments, put it in unveiling his draft report commissioned in April last year, when federal Labor was still in opposition.

It's as much a tall order at the global level. Rudd was as resolute at the Group of Eight summit in Japan as he had been in taking the issue to the election that brought his party back into government last November, after 11 years.

"The buck stops with us," Rudd said of the need for developed and developing countries to work towards a "grand consensus" on action.

It was the same message he brought to Sekolah Aminuddin Baki in Kuala Lumpur, on a stop on his way home from Japan.

Garnaut paints consequences of apocalyptic proportions, of the order Sir Nicholas Stern pressed the world into consciousness two years earlier, with his report to the British government on the economic cost of failure.

Garnaut took to the road over the past week to drive home the message, to packed town hall meetings in Perth, Adelaide, Melbourne, Sydney and Brisbane.

Among the rich countries, Australia is most at risk on climate change, because it is so dry. Rivers could stop flowing, farms could no longer operate, towns could go under to rising seas, and export prices could collapse.

The science is not in dispute, as Rudd reports at the global level. "There was no fundamental dispute about the need for global action," he said in Toyako, in Hokkaido. "What there is a disagreement about is the level of action required across the developing world and across the developed world."

The same argument rages at home, about the sharing of the cost of action. Garnaut presented the problem in his draft report released on July 4. The cheapest way to tackle greenhouse gas emissions, he suggests, is to set up an emissions trading system quickly -- within two years. There will be a cost. Dealing with global warming involves transforming the global economy from one reliant on fossil fuels.

Carbon emissions trading is only the first step. To get people and industry to modify behaviour, as incentive to develop new technologies.

Nothing can be left out, says Garnaut. Not the heavy polluters, including the power generators -- which will hit electricity bills -- and not petrol, which will add to household expenses. Dealing with the environment is fundamentally economic.

Climate Change Minister Penny Wong will present the preliminary government response in a green paper on Wednesday.

Garnaut will release a supplementary draft report late next month, with the final report due by Sept 30.

Commentators shudder over the battle ahead. Rudd's first term comes up for re-election in 2010, about the time he has committed to get started on emissions trading.

Yet Australians have shown themselves to be open to change.

Two instances stand out over the past 25 years: the economic reforms of Rudd's Labor predecessor Bob Hawke, who floated the dollar in 1983 and deregulated the economy, and when John Howard, at the head of the Liberal-National coalition, introduced the goods and services tax in 2000. Hawke had earlier in 1983 been returned to government. His government, and that of his successor, Paul Keating, was to be re-elected in four runs at the poll thereafter.

Howard remained prime minister over two more electoral cycles after the GST before he was displaced last year.

Garnaut had been senior economic adviser to Hawke and his then treasurer, Keating. As he casts his mind 25 years back, he recalls a public that was far from persuaded on the dismantling of protection in Australia. Then, people were against cutting tariffs. Today, the polls show people want Australia to tackle global warming.

The day after Garnaut released his report, people took to the streets in Melbourne demanding action. On Garnaut's five-city tour, the most heated voices came from those who thought he was not going far enough.

Doubt at the other end of the spectrum came from those whom opposition leader Nelson was appealing to. They were wondering why they -- and Australia -- should stick their necks out at a cost to the comparative advantage of the resource and fossil fuel-based Australian economy.

Garnaut may be well placed to build consensus from his broad experience. As adviser to governments, 61-year-old Garnaut has built up a formidably diverse background as economist and academic, and in business, in Australia and in the Asia-Pacific region.

Garnaut has been professor of economics at the Australian National University since 1989, where he is chairman of the China economy and business programme.

From his 1989 report to the Hawke government, Australia and the Northeast Asian Ascendancy, the honorary professor at the Chinese Academy of Social Sciences has been among economists in leading Australia's engagement in the region.

A former adviser to the Papua New Guinea government and ambassador to China, he has been on the board of directors of companies as varied as financial management and as chairman of the Lonely Planet publisher of travel guides.

As board member of numerous academic and policy institutes in Asia and in the Pacific, he is known to Malaysians at the Institute of Strategic and International Studies.

On Garnaut's broad interests and engagement, Rudd may well build confidence at home and abroad as he seeks consensus on climate change among developed and developing economies.