When Tony Blair told a reporter he was "still waiting for the first politician who's actually running for office who's going to come out and say" that we need to fly less, the headlines that followed were a measure of the way the debate over climate change has shifted. In 2005, similar remarks the British prime minister made to a parliamentary committee barely touched the news agenda. But in that time, the media here have moved on from debating the reality and the seriousness of climate change, to predicting how bad things will get and asking what needs to be done.

After years in which no BBC report on the subject was complete without airing the views of climate-change sceptics, this is progress. Where business leaders and politicians gather, there is talk of momentum, a tipping-point, history in the making. Yet behind this confidence, the fear remains that our democratic structures will not be up to the task: that the boundaries of what is politically "practical", in Blair's language, will not accommodate the kind of measures required to prevent runaway climate change.

It is this fear which feeds the visions of an authoritarian future which have begun to enter the debate from more than one side. The fact that few informed observers believe individual restraint and technological innovation will generate the necessary cuts in emissions, so that a significant increase in government intervention in individual behaviour is to be anticipated means such visions deserve to be taken seriously. They suggest that it is time to consider tackling climate change not simply as a technical problem but as a challenge to the democratic imagination.

Dougald Hine is a writer and social entrepreneur. He is currently working on an internet startup based in London. His blog is here

Also by Dougald Hine in openDemocracy (originally published anonymously):

"China's days of protest" (17 June 2004)

The discontents of dystopia

Perhaps the most powerful imaginative account of such an authoritarian near-future is Alfonso Cuarón's film Children of Men. Set in 2027, the immediate explanation for the global crisis which surrounds its characters is an unexplained, total collapse of human fertility: a threat to the future of humanity so direct as to be allegorical. Yet the film gets its charge from the newspaper clippings and other glimpsed ephemera which hint at how its world has emerged from ours. Most elements of its nightmare are only extensions of situations already found in some parts of the world, while their escalation feels plausible because the direr predictions of the human consequences of climate change increasingly match the realities of our experience.

A central element in that nightmare is the brutal government measures taken to contain vast numbers of refugees desperate to reach safety in Britain. This picture of catastrophic mass migration pushing liberal democracy beyond its limit features in the background of another dystopian vision. The commentator Madeleine Bunting imagines explaining to her grandson, forty years on, why we were so slow to tackle climate change. Her letter from the future recalls, in passing, the African exodus of the 2020s - "those years of barricaded Mediterranean ports and boats sinking under their starving freight" - but this is incidental to her theme, which is our unreadiness for the measures required at home. "The problem was that we were intoxicated with an idea of individual freedom... The idea that the most precious freedom of all was freedom from fear gained force much later."

Life in 2046 is regulated, monitored and micro-managed down to the level of the local "carbon usage committee" which determines how often the octogenarian Bunting can boil the kettle or turn on her heating. Her generation, which for too long resisted the necessity of such "state intrusion", has been left to grow old "on the shores of a flooded city"; the young, meanwhile, are relocated to the "new settlements" in Scotland.

Such predictions undoubtedly confirm the prejudices of those libertarians for whom global warming is simply a socialist plot, cooked up by the losers of the cold war. This theory has little following in Europe, but a Jesuitical variant of it enters the British debate through the articles of the group associated with the current-affairs website Spiked. They accuse those who advocate action of misrepresenting the science, stifling debate and posing a threat to freedom of speech which is more serious than the (unproven) threat of climate change itself. The site's editor, Brendan O'Neill of campaigners on the national climate march in November 2006, said: "What united them all... was a petty authoritarianism... This was in essence a demo demanding less debate and more stringent measures outlining what people can do and consume."

O'Neill delivers that summary of the marchers' demands as if unmasking a dark motivation behind their fluffy exterior. Yet it is a measure of the strangeness of this debate that the protest's headline speaker, George Monbiot, frames his proposals for tackling climate change in just those terms. On the final page of his impressively detailed book, Heat: How to Stop the Planet Burning, readers are urged to make the "imaginative leap" necessary to demand the implementation of his recommendations:

"For the campaign against climate change is an odd one... It is a campaign not for abundance but for austerity. It is a campaign not for more freedom but for less. Strangest of all, it is a campaign not just against other people, but also against ourselves."

The publicity accompanying the book plays on this demand for less freedom: a series of posters features public figures whose eco-friendly image is unlikely to stand up to scrutiny and the slogan "George Is Watching You".

Meanwhile, as Monbiot plays with the iconography of totalitarianism, others are gearing up to capitalise on the political instability that could arise from the impact of climate change. Nick Griffin, leader of the British National Party, reportedly sees in it a "once-in-200-years opportunity" for the far right.

Also in openDemocracy's debate on the politics of climate change:

John Elkington, "After Stern: let's get technical" (2 November 2006)

Saleemul Huq & Camilla Toulmin, "Climate change: from science and economics to human rights" (7 November 2006)

Simon Retallack, "Climate change: the global test" (10 November 2006)

Tom Burke, "Climate change: choosing the tools" (21 December 2006)

Caspar Henderson, "The president's new clothes" (24 January 2007)

John Elkington & Geoff Lye, "Climate change's right and wrong fixes" (2 February 2007)

Oliver Tickell, "Climate change: the last chance" (6 February 2007)

The democratic telescope

Al Gore, introducing the British premiere of An Inconvenient Truth in Edinburgh in August 2006, took his audience on a detour through the political philosophy of the Frankfurt School. His aim was a line from Theodor Adorno's Minima Moralia, in which the emergence of the Third Reich is identified with "the reconfiguration of all questions of truth into those of power." Although he is wary of appearing to make a direct analogy, Gore sees a similar tendency at work in today's America, and this frames his thinking about tackling climate change:

"In order to solve the climate crisis we have to address the democracy crisis... I believe that a campaign that's based on a very large set of ideas focused on the future and the public interest now faces such a withering headwind that a higher priority is to change democracy and open it up again to citizens... and to democratise the dominant medium of television, which has been a form of information flow that has stultified modern life."

On climate change itself, Gore's speeches are optimistic yet deliberately vague about the full implications of reducing emissions. This may be shrewd tactics, but others see the public reaction to his campaign as confirming Monbiot's fear that we will look for leaders who "pretend to act" so that "we get the moral satisfaction of saying what we know to be right, without the discomfort of doing it." (In this role, the argument might go, what could be better than an undoubtedly presidential figure unencumbered by the reality of power.)

Yet if Monbiot has a warning for Gore, the same applies in the other direction. Paradoxically, America's failure to rise to the challenge of climate change, related as it is both to the effects of political funding and the incapacity of the mass media to hold government to account, has sensitised its campaigners to the importance of democratic renewal.

Listening to British campaigners, it can sound as though the problem is that we as individuals have too much power and the state has too little. What Gore reminds us is that, in important ways, power is already dangerously concentrated. There are signs of hope, not least in some of the ways which people are finding to use the internet. Mechanisms for restricting our personal behaviour will be required, but we should demand involvement in the process rather than petitioning the state to relieve us of our freedom. Meanwhile, governments must stop protecting those industries which cannot or will not adapt their behaviour to a low-carbon world.

Climate change presents immense technical tests, but the challenge it presents is also to the democratic imagination. Whether or not we succeed technically in mitigating its effects, it is all too easy to envisage the result as a more or less unpleasant authoritarian future. The task is to imagine and bring about a future which can accommodate both austerity and autonomy. There is a kind of political freedom which is distinct from consumer freedom and also from the "freedom from fear" promised by pervasive state control. At its heart is the space for individual and shared self-reliance. The tone of much current debate over climate change makes the rearticulation of this idea of freedom urgent.