There is no meaningful response to climate change without massive social change. A cap on this and a quota on the other won't do it. Tinker at the edges as we may, we cannot sustain earth's life-support systems within the present economic system.

Capitalism is not sustainable by its very nature. It is predicated on infinitely expanding markets, faster consumption and bigger production in a finite planet. And yet this ideological model remains the central organising principle of our lives, and as long as it continues to be so it will automatically undo (with its invisible hand) every single green initiative anybody cares to come up with.

Much discussion of energy, with never a word about power, leads to the fallacy of a low-impact, green capitalism somehow put at the service of environmentalism. In reality, power concentrates around wealth. Private ownership of trade and industry means that the decisive political force in the world is private power. The corporation will outflank every puny law and regulation that seeks to constrain its profitability. It therefore stands in the way of the functioning democracy needed to tackle climate change. Only by breaking up corporate power and bringing it under social control will we be able to overcome the global environmental crisis.

On these pages we have been called on to admire capital's ability to take robust action while governments dither. All hail Wal-Mart for imposing a 20% reduction in its own carbon emissions. But the point is that supermarkets are over. We cannot have such long supply lines between us and our food. Not any more. The very model of the supermarket is unsustainable, what with the packaging, food miles and destruction of British farming. Small, independent suppliers, processors and retailers or community-owned shops selling locally produced food provide a social glue and reduce carbon emissions. The same is true of food co-ops such as Manchester's bulk-distribution scheme serving former "food deserts".

All hail BP and Shell for having got beyond petroleum to become non-profit eco-networks supplying green energy. But fail to cheer the Fortune 500 corporations that will save us all and ecologists are denounced as anti-business. Many career environmentalists fear that an anti-capitalist position is what's alienating the mainstream from their irresistible arguments. But is it not more likely that people are stunned into inaction by the bizarre discrepancy between how extreme the crisis described and how insipid the solutions proposed? Go on a march to the House of Commons. Write a letter to your MP. And what system does your MP hold with? Name one that isn't pro-capitalist. Oh, all right then, smartarse. But name five.

We are caught between the Scylla and Charybdis of climate change and peak oil. Once we pass the planetary oil production spike (when oil begins rapidly to deplete and demand outstrips supply), there will be less and less net energy available to humankind. Petroleum geologists reckon we will pass the world oil spike sometime between 2006 and 2010. It will take, argues peak-oil expert Richard Heinberg, a second world war effort if many of us are to come through this epoch. Not least because modern agribusiness puts hundreds of calories of fossil-fuel energy into the fields for each calorie of food energy produced.

Catch-22, of course, is that the very worst fate that could befall our species is the discovery of huge new reserves of oil, or even the burning into the sky of all the oil that's already known about, because the climate chaos that would unleash would make the mere collapse of industrial society a sideshow bagatelle. Therefore, since we've got to make the switch from oil anyway, why not do it now?

Solutions need to come from people themselves. But once set up, local autonomous groups need to be supported by technology transfers from state to community level. Otherwise it's too expensive to get solar panels on your roof, let alone set up a local energy grid. Far from utopian, this has a precedent: back in the 1920s the London boroughs of Wandsworth and Battersea had their own electricity-generating grid for their residents. So long as energy corporations exist, however, they will fight tooth and nail to stop whole postal districts seceding from the national grid. Nor will the banks and the CBI be neutral bystanders, happy to observe the inroads participatory democracy makes in reducing carbon emissions, or a trade union striking for carbon quotas.

There are many organisational projects we can learn from. The Just Transition Alliance, for example, was set up by black and Latino groups in the US working with labour unions to negotiate alliances between "frontline workers and fenceline communities", that is to say between union members who work in polluting industries and stand to lose their jobs if the plant is shut down, and those who live next to the same plant and stand to lose their health if it's not.

We have to start planning seriously not just a system of personal carbon rationing but at what limit to set our national carbon ration. Given a fixed UK carbon allowance, what do we spend it on? What kinds of infrastructure do we wish to build, retool or demolish? What kinds of organisational structures will work as climate change makes pretty much all communities more or less "fenceline" and almost all jobs more or less "frontline"? (Most of our carbon emissions come when we're at work).

To get from here to there we must talk about climate chaos in terms of what needs to be done for the survival of the species rather than where the debate is at now or what people are likely to countenance tomorrow morning.

If we are all still in denial about the radical changes coming - and all of us still are - there are sound geological reasons for our denial. We have lived in an era of cheap, abundant energy. There never has and never will again be consumption like we have known. The petroleum interval, this one-off historical blip, this freakish bonanza, has led us to believe that the impossible is possible, that people in northern industrial cities can have suntans in winter and eat apples in summer. But much as the petroleum bubble has got us out of the habit of accepting the existence of zero-sum physical realities, it's wise to remember that they never went away. You can either have capitalism or a habitable planet. One or the other, not both.

Email to: rnewman@dircon.co.uk