The northern hemisphere's late summer began with a renewed period of global financial turbulence which - almost immediately - provoked massive and sustained intervention by governments and central banks to keep the system afloat. There are serious arguments over whether such intervention is the best way to manage an economic model fuelled by runaway debt, opaque or ineffective regulatory systems, and institutional practices remote from the daily lives of the citizens they are supposed to serve. But the fact of government involvement in the economy is central to this unfolding drama.

The reverberations of the financial crisis will be felt for months, perhaps years to come. As they come to be, it may be tempting to forget the departed summer of 2007 as just another phase of extraordinary - yet now routine - extremes in the world's weather systems: vast floods from England to Africa, devastating forest-fires in Greece, a seemingly never-ending drought in Australia, melting ice-floes around a greening Greenland. This combination - and many more examples could be given - provides further evidence for the prediction that climate change will play havoc with hitherto relatively stable weather patterns, in the context of a long-term, global rise in temperature.

But the temptation to forget should be resisted, and not just because these events are also processes - part of the permanent reality that is reshaping our lives, which we must understand and respond to if we are to survive. The reason to remember is also in the contrasting response by governments to these environmental crises: too often belated, provisional, and fragmented. If governments can recognise a cyclical financial emergency and in an instant move heaven and earth (and billions of dollars, pounds sterling and euros) to contain it, why can't they do the same in response to a permanent environmental emergency?

The space of politics

There is a range of possible answers to this question: institutional, ideological, interest-laden. A less obvious one touches on the way the public argument about the environment and climate change is now being conducted: who is included, who is excluded (or self-excluded), and what forces are seen as available (or not available) to make a difference.

Andrew Dobson is professor of politics at Keele University. Among his books are Citizenship and the Environment (Oxford University Press, 2003), (as co-editor) Political Theory and the Ecological Challenge (Cambridge University Press, 2006) and Green Political Thought (Routledge, new edition, 2007). His website is here

Also by Andrew Dobson in openDemocracy: "A politics of global warming: the social-science resource" (29 March 2007)

To illustrate this point, the recent flurry of "green" activity among Britain's leading political parties is notable. The opposition Conservatives have published a huge quality-of-life document following eighteen months' work by a committee involving the Ecologist editor Zac Goldsmith; the "third-party" Liberal Democrats have produced a comprehensive environmental plan revolving around higher eco-taxes; while the Labour government's gesture in this direction has been the welcome by prime minister Gordon Brown of Swedish businessman Johan Eliasch into his increasingly capacious "big tent".

Eliasch is a former deputy treasurer of the Conservative Party (and member of the advisory board of Iain Duncan Smith's Centre for Social Justice). He has bought 1,600 square kilometres of Amazon rainforest to protect plants and wildlife - one example of the increasingly fashionable move by wealthy individuals in the direction of what has come to be known as "green colonialism".

On one view, all this activity (including Eliasch's - and Brown's - political cross-dressing) is evidence of broad agreement on the importance of climate change and the environment; something which, therefore, should be unreservedly welcomed. On another, though, the content of these initiatives only serves to emphasise that one political actor is strikingly absent: the state itself. Neither the Liberal Democrats nor the Conservatives are natural supporters of strong government in the environmental or economic sphere; and the entry of Eliasch into the orbit of Labour's incipient "government of all the talents" sends the strong signal that rich individuals are better placed than elected governments to lead the way to sustainability.

In pre-celebrity days, NGOs, charities and activist groups would try to persuade governments to set aside land for sustainable development in the interests of both indigenous peoples and the plants and animals on which they depend. Now, the core decision-making seems to be left to individuals with neither roots nor political legitimacy in the land they own 12,000 miles away. The democratic movement in the early 20th century that resulted in the establishment of national parks throughout Europe is being replaced by a new reliance on wealthy individuals. This situation is not so different from the days when the landed aristocracy were responsible for "protecting" the land and the people whose habitat it is - only today, the symbol of the new environmentalism is cheque-books rather than deer-stalkers.

The tendency of political parties to ignore or downplay the role of the state is unwise. Democratic governments, after all, possess the political legitimacy derived from a popular mandate that individuals and other organisations lack; they can also do things that these other forces cannot (e.g., passing laws that change behaviour for the better - such as a ban on smoking in public buildings). Britain, more than most European countries, is not well equipped culturally to provide strong pro-environmental government after a thirty-year-long political experiment that has hollowed out public life and corroded or destroyed "public capital". The "nanny state" has become a useful libertarian cliche that often makes it difficult for government to act in the interests of the common good - which is of the essence of a sustainable environment.

The roar of denial

The role of the state as an active agent of democratic environmentalism is a key point of difference in the political cultures of Britain and much of continental Europe. Where government is not held in contempt but seen as a defender of the common good and an impartial actor worthy of support, it can also be supported in its actions against (for example) industry-led pollution or unfair profiteering.

One important battleground in the European Union is the automotive industry. For some time the EU has sought a mandatory upper limit of 120 grammes per kilometre (g/km) of Co2 for new cars by 2012. Only 25% of new models sold in Britain fall within even the <100 to 150 g/km bracket, so it's easy to see how much work there is to do in the next five years. This is a test case for so-called "ecological modernisation": the idea that sustainable development and economic growth are not in contradiction, because industry can profit from strong environmental regulations by building and selling more environment-friendly products.

The automotive industry is in theory a perfect ecological-modernisation (or EM) sector, for three reasons:

* there is plenty of room for improvement
* the required regulations are easy to set up and understand (like the 120 g/km limit)
* car manufacturers are constantly updating their models, which gives them the chance to make rapid progress towards meeting government-led targets.

Meanwhile, the environment-led argument for government regulation is that voluntary targets are consistently missed - motor manufacturers in Europe, Japan and Korea have all missed such targets for 2008-09.

The automotive industry's response to this "opportunity" has been - to put it mildly - less than enthusiastic. Britain's Society of Motor Manufacturers and Traders has expressed "grave concerns" about the proposals, which it said would result in less choice and higher prices for consumers. The society's chief executive, Christopher Macgowan, says: "We have already produced and brought to market cars that can meet the 120g/km limit - the problem is that motorists do not buy them". Indeed, but the whole idea behind a statutory limit set by government is that motorists would have to buy what was on the forecourt, in the general as well as their individual interest.

Macgowan also says: "Not only will the choice of cars be reduced by these measures if we are to meet the limits, but independent estimates place a projected increase in the region of £2,500 to the sale price of each new car'. This is an odd remark. A Toyota Prius (104 g/km) costs £17,765, and a Lamborghini Murcielago (495 g/km) costs £195,500 - so it's quite clear that relatively low-emission cars can be built and bought for lower prices than the motorists' champion seems to think.

The lessons from the automotive industry's resistance to an absolutely essential element of climate-change policy are a case-study in the role of the state (often working through inter-governmental bodies such as the European Union). The lessons are threefold, and need to be learned:

* voluntary codes of practice won't work
* relying on the profit motive to set societies on the road to sustainability won't work either
* ecological modernisation requires levels of imagination and a readiness to take risks that can't be assumed to be widespread in the private sector.

The state at the centre

All this suggests that sustainability needs a kick-start. Where is it going to come from? The private sector has its limitations; the voluntary sector is just that - voluntary; civil society can be a source of social experimentation, but it is hard to see how it can reach into all corners of social and political life to the degree required.

This leaves the state as an under-explored agent for sustainability. Such a proposal need not raise the fear of the "green Leviathan" that was so popular among some early environmentalists, especially in north America. The social-democratic states of Scandinavia are a good example of what can be done in rising to the sustainability challenge, far more than liberal-capitalist states like Britain and the United States.

But the argument is not limited to particular states or outcomes. Once we know what is the right thing to do, it seems folly to pass up the opportunity to do it. This means discarding the ideological trappings of an increasingly discredited neo-liberalism - such as the fetish of consumer choice, or the notion of the small state. The financial tsunami that has caused bankers to fear, depositors to panic, and governments to act reflect an economic system thatplays with our future as if it were a number on a roulette wheel. An active eco-state will never be the whole answer to the epic challenge of climate change, but it surely forms a bigger part of it than is yet recognised. As a sweltering summer fades to black, and an autumn chill descends, it is time to put government at the centre of the argument for sustainability.