This post was first published at ABC's Unleashed site:

With the global financial meltdown meeting the climate meltdown head on, the potential to deal with both crises using the same solutions has been gaining support.

Last month, the United Nations Environment Program joined with Deutsche Bank and others to promote a 'Green New Deal' based on investing billions of dollars in the four pillars of renewable energy, energy efficiency, clean transport and ecosystem protection, reducing greenhouse emissions, building infrastructure and creating millions of new jobs. World leaders such as US President-elect Obama, UK Prime Minister Gordon Brown and UN Secretary General Ban Ki-Moon have publicly embraced the proposal, with Obama listing a $150 billion clean energy plan as his top priority.

The 'Green New Deal', taking its inspiration from Franklin Delano Roosevelt's 'New Deal' to build the USA out of the Great Depression, is only the most recent embodiment of strategies put forward from Hobart to London over the last few decades, recognising that investing in protecting the environment is the only sensible economic plan.

The Greens have long been arguing that Australia's economic future depends on investing our current wealth in a clean, zero emissions future. Since the beginning of the current economic crisis, we have been calling for a 'Green New Deal' at home and for any economic support package to be directed at sustainable alternatives. A key aspect of this is our proposal to retrofit every home in the nation with energy efficient technologies such as solar water heaters and insulation.

That's why, after weeks of silence from the Rudd Government, I was delighted to hear the Prime Minister and his Industry Minister, Senator Carr, at least start using this language in launching their Green Car Package last week. Both noted that it was only by building environmentally sustainable cars that Australia's car industry can have a sustainable future - something I have been telling them for years.

But the devil, as always, is in the detail. And so much of that detail is still missing - right down to what is the definition of a 'green car' that will benefit from the package.

I welcomed the plan as the first step in recognising the importance of linking economic stimulus measures to the effort to build a new, zero emissions economy. But, in doing so, I noted that it was a small first step and that the Greens look forward to working with the Government to flesh it out.

Here is what we would propose:

In rethinking transport for a zero emissions Australia, the fundamental points are to help people to drive less and, when they do drive, to drive more efficiently and with the least polluting vehicles possible.

There is no reason why the Green Car Plan could not have been presented as a Green Transport Plan that would shift car manufacturing onto a green base and drive investment and job creation in rolling out buses, trains, ferries, trams and cycleways. Instead of thinking small, with changes at the margins to make cars that little bit more fuel efficient, we could see a plan to roll out an electrified vehicle fleet and all the infrastructure that will have to go with that - powered by a massively increased renewable energy grid, of course. American entrepreneur Shai Agassi has already proposed rolling out electric vehicle infrastructure in Australia. He should be given all the help he can to make it a reality. Agassi is only one of many entrepreneurs promoting intelligent networks, such as digital control systems for railways and smart electricity grids, which create significant efficiencies and make it easier to have an energy system powered entirely by renewable energy.

As well as investing in the infrastructure for public transport and electric vehicles, the Government should be investing in R&D and commercialisation for second generation biofuels which present a real potential for zero emissions transport without reducing availability of food crops or replacing standing forests with oil palm plantations, for example.

Aside from direct spending, there are plenty of big changes that can be encouraged through the tax system. The Greens achieved a small win by exempting fuel efficient vehicles from the Luxury Car Tax, already leading Audi to sell more efficient cars in Australia, but we propose a much broader tax shift to drive cleaner transport. We would replace the Luxury Car Tax altogether with a tax based on the fuel consumption of vehicles rather than their sale price. We would remove the Fringe Benefits Tax Concessions that encourage people to drive more. We would also take the GST off public transport fares.

When it finally decides how to define a 'green car', we will be calling on the Government to implement mandatory vehicle fuel efficiency standards. China and Europe are powering ahead of Australia with stringent standards in place and, without them, Australia will be left behind, regardless of the rhetoric of the Prime Minister and Industry Minister.

One policy the Government has ignored altogether is the tremendous impact of changing government procurement policies to buy more efficient and hybrid cars for the government fleets. Because of the fast turnover in these fleets, this simple change has a large flow-on effect by driving many more efficient vehicles into the second hand market.

The Government has not yet embraced very much of this obvious agenda. But, with the Green Car Plan, they took the first step of recognising that the economic meltdown and climate meltdown could be addressed at the same time. There is much more to be done but, perhaps encouraged by the election of Barack Obama, we can have some hope of stronger action in that direction in 2009.