Gwynne Dyer, Contributor

Here's the plan. Everybody in the country will get the same allowance for how much carbon dioxide they can emit each year, and every time they buy some product that involves carbon dioxide emissions - filling their car, paying their utility bills, buying an airline ticket - carbon points are deducted from their credit or debit cards. Like air miles, only in reverse.

So if you ride a bike everywhere, insulate your home, and don't travel much, you can sell your unused points back to the system. And, if you use up your allowance before the end of the year, then you will have to buy extra points from the system.

This is no lunatic proposal from the eco-radical fringe. It is on the verge of becoming British government policy, and Environment Secretary David Miliband is behind it 100 per cent. In fact, he is hoping to launch a pilot scheme quite soon, with the goal of moving to a comprehensive national scheme of carbon rationing within five years.

A huge share of total emissions is driven by the decisions of individual consumers. Miliband thinks that the least intrusive, most efficient way of shaping those decisions is to set up a system that tracks everybody's use of goods and services that produce a lot of greenhouse gases, and rewards the thrifty while imposing higher costs on the profligate. And, there is no time to lose. The world's carbon emissions have to stop growing within 10 to 15 years, he says, and Britain must cut its total carbon emissions by 60 per cent in the next 30 or 40 years.

Dangerous place

"We are in a dangerous place now," he told the Guardian newspaper on December 11, "and it is going to be very difficult to get into a less dangerous place. The science is getting worse faster than the politics is getting better. People know the technology exists to get a lot of this done ... but there is a huge chasm of mistrust between countries about how to do this. ... The developing countries won't take on any carbon-reduction targets until they believe the countries that have caused the problem do so."

The science certainly is "getting worse", in the sense that every forecast is worse than the one before. The most recent assessment of the state of the Arctic by the International Panel on Climate Change, whose full fourth report is due next year, was published early in the journal Geophysical Research Letters last week because its forecast was so alarming.

If current trends persist, the scientists reported, the Arctic Ocean will be entirely ice-free in the summertime, not in 2080, as previous forecasts suggested, but by 2040, just 33 years from now. Then the dark ocean surface absorbs much more heat than the reflective ice did, and another element of feedback kicks in, and the speed of warming increases again ...

Huge chasm of mistrust

Those in the know are very frightened, but there is still that "huge chasm of mistrust". The developing countries that are only now beginning to emit large amounts of greenhouse gases look at the mountain of past emissions produced by the developed countries, the source of most current climate change, and they want the rich countries to cut back very deeply - deeply enough to leave the developing countries some room to raise their consumption without dooming us all to runaway climate change.

That's where the long-range target of 60 per cent emission cuts for Britain comes from. Britain only produces two per cent of global greenhouse gas emissions, so a 60 per cent cut in Britain alone is still only a drop in the bucket, but the aim is to set an example: See, we can do this without impoverishing ourselves, so other developed countries can, too. And if they do, then a deal to control the growth of emissions in the developing countries is within reach.

So individual carbon credit accounts for all, and if you want to do things that produce more carbon dioxide than your annual allowance, you pay for it. The frugal and the poor can sell their unused credits back into the system - and every year or so, as the average carbon efficiency of transport or food production or power generation improves a little bit, the size of the free personal carbon allowance is reduced a little bit. It is, I suspect, the shape of things to come.

Gwynne Dyer is a London-based independent journalist whose articles are published in 45 countries.