Australian ministers on Tuesday said environmental activists were living in "fantasy land" after plans to disrupt the country's coal export boom were revealed.

Greenpeace is spearheading a multi-million dollar campaign to delay key projects and infrastructure by eroding public support for the coal industry while funding legal challenges against controversial mines.

The plan also involves exploiting opposition to coal-seam gas to put pressure on governments to block mining, The Australian reported, citing confidential documents.

Australian resources, including coal, are in big demand from developing countries such as India and China as they build power projects to fuel their fast-growing economies.

But environmentalists are concerned about the impact of the boom on farmland and groundwater aquifers, as well as the consequences for climate change.

"If we fail to act decisively over the next two years, it will be too late to have any chance of stopping almost all of the key infrastructure projects and most of the mega-mines," the Greenpeace-led coalition said.

It added that it was seeking investment "to help us build a nationwide coal campaign that functions like an orchestra with a large number of different voices combining together into a powerful symphony".

Trade Minister Craig Emerson said the concept was "recklessly irresponsible" while Treasurer Wayne Swan labelled the anti-coal movement "irrational" and "destructive".

"The idea of flicking a switch from coal and other fossil fuels to renewable energy cannot be done," said Emerson.

"We would have a global depression if we just said 'that's it, we're out of coal, we are just going to move to renewable energy' just because they believe that is good for the world.

"It would mean mass starvation and they ought to wake up to that, instead of living in a fantasy land and organising these sorts of campaigns."

The trade minister said Australia was tackling issues of concern by putting a price on carbon pollution from July 1.

From that date, a levy of Aus$23 (US$23.80) per tonne of carbon emissions will apply before the country moves to an emissions trading scheme in 2015.

With the Australian Coal Association calling the campaign "economic vandalism", Prime Minister Julia Gillard moved to reassure miners that the government strongly supported the sector.

"The coal industry has got a great future in this country. We've made that clear all along. You're seeing that future being built now as we see expansion in our coal exports particularly," she said.

Greenpeace Australia's John Hepburn, co-author of the campaign document, told ABC radio there were legitimate concerns about the scale of the mining boom.

"We're looking at mega-mines that would increase Australia's coal exports two or threefold within the next 10 years, with massive impacts on our best farmland, on our groundwater aquifers, on the global climate," he said.

"And they're also having a big negative impact on the economy, destroying jobs in manufacturing, agriculture and tourism. So we think it's completely legitimate."

Mining-powered Australia was the only advanced economy to dodge recession during the global downturn due to the resilience of resources exports to Asia, but other parts of the economy are struggling due to the strong local dollar.