The fear is that the environment will get trampled in the rush to reboot the old-style exploitative economy, but there is hope in the opportunity to build something different.

Just as mammals only inherited the Earth after the dinosaurs were smacked by an extra-terrestrial rock, a sustainable economy might only compete when the old beast no longer roars.

Now as it whimpers, can true sustainability thrive?

Speak no evil...

We fly less; we drive less; we burn less oil and gas and dig up fewer mountains to provide iron ore, bauxite or copper.

Look back at post-war graphs and you'll find the most reliable way to cut carbon emissions is an economic depression.

For years, environmentalists have preached on the evils of rampant consumerism; now we have got the opposite, are they smiling?

Barely, and not just because they risk offending former Woolworths or Nissan workers.

The recession has also revealed the shallowness of that philosophy. If being pro-environment means simply being anti-economy, that means unemployment, social unrest and six billion people in serious trouble.

Stephen Hale from lobbying group Green Alliance says the first change environmentalists should make is in their language.

"I think it needs to be totally rethought by the people who have to develop and present solutions that appeal to the electorate," he told the BBC.

"I don't believe that we're going to make real progress in the current climate by describing issues like climate change as environmental. That makes them feel like a luxury choice."

Losing momentum

In short, they are using the "being green is a luxury" argument.

Ruth Lea, former director of the Institute of Directors, says Britain could risk becoming uncompetitive.

"The sort of green policies that we already see are undoubtedly pushing up the electricity cost to business," she said.

"That undermines various types of industry in this country.

"Indeed, as far as Mrs Merkel is concerned in Germany, and Silvio Berlusconi in Italy, they are not going to threaten their industries by having these green policies as strongly as we are."

So is the government striving to realise a new vision of Britain that is both green and pleasant?

Most commentators say there's scant evidence of it yet.

Sir David King, former government chief scientific advisor and the man who grabbed attention by saying that climate change was a greater threat than terrorism, is unimpressed by their actions so far.

"Perhaps it's not only ministers, but the mandarins in the Treasury who haven't bought into the need to decarbonise," he suggested.

"I think what we need [is a] Treasury tsar to cost up delivering decarbonising our economy. Until such a person is appointed I think one has to remain rather sceptical."

Out of tune?

They take every opportunity to urge the band of bankers, business people and builders to strike up the old tune. Yet, is it still a dance-floor filler?

The argument comes to a head with the government's own decisions and spending.

Will it give the go-ahead to a third runway at Heathrow, or new road building?

Such projects provide well paid jobs but at some cost to our environment. The balance may be found in funding greener projects.

The recession has prompted a change upfront in the economic bandwagon: the government and the market swapping places.

Suddenly, the politicians are in the driving seat, giving them enormous power to pull green levers should they wish.

President-elect Obama seems to want to grab some of them - talking about enormous investments in renewable energy and only bailing out the car industry if it becomes cleaner. This is the so-called Green New Deal.

Will this prove to be the creative spark to fire up an economy based on sustaining our resources rather than exhausting them, or is it simply a flash in the pan?

Remember the character Gordon Gecko, from the film Wall Street, proclaiming that "greed is good"?

He boiled down the capitalist economic machine - I want something, you provide it, I pay you; the more I want, the faster it runs.

The challenge for environmentalists, during this recession, is grabbing this moment of doubt and pain to find an alternative; making greed work to support our world, not destroy it.