Mr Rudd and Senator Wong were to stay at the city of Sapporo before travelling to the summit venue this morning.

Before he boarded the plane yesterday morning, Mr Rudd had conservative expectations regarding the outcome of today's talks.

''It is unrealistic to expect a dramatic breakthrough at this meeting,'' he said.

Mr Rudd and Senator Wong will put Australia's case for change at today's G8 ''outreach meeting'' involving 16 countries responsible for 80 per cent of global greenhouse gas emissions.

''On the question of climate change, I will be engaging world leaders on the need for us to all achieve real progress on the post-Kyoto road map,'' Mr Rudd said in Canberra before he headed to the summit.

''This is critical for the planet, and critical for Australia.

''We are the world's hottest and driest continent already and therefore, we run the risk of being hit earliest and hardest when it comes to climate change.''

In his recent report to the Government, economist Professor Ross Garnaut recommended emissions trading should be in place by 2010 in a bid to stave-off disaster.

Mr Rudd said yesterday that the Government's ambition, intention and plan was to set up the system by 2010 in line with Labor's election promise.

Professor Garnaut has warned the emissions trading scheme could be compromised without bipartisan support, which appeared increasingly unlikely.

Opposition Leader Brendan Nelson said it would be economic ''suicide'' to introduce a scheme before other countries such as the US, India and China.

''For Australia to go it alone, well in advance of the rest of the world, will do irreparable damage to our economic future and not do a darn thing to address climate change and an environmentally sustainable future for the planet,'' Dr Nelson said.

It was seen as a policy U-turn after the Coalition made the pre-election pledge to establish a scheme by 2012.

Deputy Opposition Leader Julie Bishop said yesterday the party remained ''committed to that policy''.

But the Coalition's approach to climate change and emissions trading was criticised by Susan Jeanes a former Liberal MP and adviser to Senator Robert Hill when he was environment minister.

''I think it's time that the Coalition tackled the hard questions. I think we've been ducking it for too long now,'' Ms Jeanes told ABC Radio.

''Now 10 years down the track, the country is going through this process again, looking at what are the design features that are in our national interest.

''Certainly delaying is not in our national interest and I think it is time for the Coalition to shape the process as opposed to oppose it.''

with agencies