Liberal Leader Brendan Nelson said the Coalition supports an emissions trading scheme (ETS) and "real and practical steps to reduce emissions".

"Under our watch, Australia was one of a very small number of countries to be on track to meet its international emissions targets," Dr Nelson said.

"Professor Garnaut has confirmed how significant the process of an emissions trading scheme will be – for our environment, for our economy and for all Australians.

"If Mr Rudd can botch something as basic as solar panels on roofs, he needs to be very careful to get the details right with such a significant reform – for the sake of Australia's motorists, households, pensioners, businesses, jobs, economy and environment."

When asked today whether further increases in the price of petrol should be offset, Professor Garnaut said: "I don’t see any good reason to do it."

But Dr Nelson says that with petrol now at $1.70 a litre, Australians have already received a significant price signal on petrol.

"The Coalition is determined to protect Australian motorists from an additional tax on petrol," he said.

Dr Nelson said there must also be a "global response which involves the world's major emitters – China, India and the United States in particular" - and not just Australia acting alone.

"Australia must also know precisely the price that will be paid before Mr Rudd formally commits us to the new international agreement on climate change in 2012," he said.