Hearing that I'm an environmental consultant, people often ask me what they should buy to reduce their climate-change impacts. A Toyota Prius? A condensing boiler? Solar panels? Reminding myself that it is indeed progress they are even asking, I try to say something positive about whatever gizmo has caught their fancy, but add that the really big, foolproof savings come from just using less. The truly green consumer is the sparing consumer, who turns heat, lights and appliances down or off (not just to standby) whenever they're not actually needed; plans their life so as to drive and fly as little as possible, and meets their needs with relatively few, simple, durable and local products.
Alas, turning off is also a turn-off. The assumption that the solution to any of life's problems must be to buy another piece of equipment is deeply entrenched. So, I want to explain why obviation - arranging our lives to use less energy - is necessary, and surprisingly easy, provided the government does its bit.
The problem with technical fixes is simply that they are not working. There are several reasons. First, the "rebound effect" - making something more efficient makes it cheaper, so people tend to use or consume more of it.
Second, growth increases consumption. Total car-fuel consumption has increased steadily for decades (except for a brief blip caused by fuel-price rises just before the 2000 protests) because we've been driving more, and this is partly because motoring has got steadily cheaper in relation to incomes.
Third, technical fixes often just displace or defer problems. Nuclear power is low carbon at the point of generation, but brings a huge tail of waste-management cost and responsibility as well as safety, terrorism and proliferation worries. Hydrogen, often presented as a clean source of energy, is no such thing: it's only a means of storing power. And Gordon Brown's flagship renewable transport fuels obligation will accelerate destruction of rainforests to make way for oil-palm plantations - the cheapest source of biofuels in new Labour's darling, global-free market.
In contrast it can be surprisingly easy to reduce energy demand dramatically. Architects Brenda and Robert Vale built a house in Southwell, Nottinghamshire, with no mains electricity or gas connection (or water or sewerage) and no fossil-fuel use. Unlike self-important "green" houses that look like they have crash-landed on arrival from Planet Zog, this dwelling looks ordinary. Its features are simple: thick heavy walls and floors to store heat and even out fluctuations (the same method that has kept Egyptian mud-brick buildings blissfully cool for 5000 years); lots of insulation in the roof and north walls (reminiscent of the tradition of piling hay in upland farmhouse lofts); and a big conservatory to trap solar heat. Thanks to these three simple measures, the house keeps snug just from the occupants' body heat and cooking and appliances, which are powered by solar panels, the only hi-tech installation used.
The BedZed development in south London achieves carbon neutrality at neighbourhood scale, again thanks largely to thorough application of the simple principles of thermal mass and controlled solar gain - abetted by terraced layout, which, as the Georgians demonstrated, combines resource frugality with adaptability.
So we already know how to build housing to near-zero carbon emissions. The barriers aren't technological, but institutional and perceptual. Most house builders do the regulatory minimum, so low-energy construction stays a niche market at a premium price. This reinforces perceptions that it is odd and eccentric, making house buyers nervous about it. Volume house builders conclude there is no demand and continue complacently building and selling energy sieves.
We could easily break this vicious circle with a bit of boring, old-fashioned regulation to require developers to achieve zero net-carbon emissions in return for the huge house-building bonanza the government is bestowing on them. This would kickstart a serious energy efficiency industry. Economies of scale would come soon enough and, for as long as better energy performance did cost more, house builders could compensate by paying less for land. Ones with big land banks might catch a cold, but that would serve them right: it is not government's responsibility to safeguard speculators' profits. Higher mandatory energy standards pay for energy savings and cost reductions for "hard-working families" out of land-speculation profits. Put like that, it's a no-brainer.
All the numbers in this field are slippery, and sensitive to assumptions. But good, independent research makes a strong case that the energy consumption of existing housing stock could be reduced by around 60 per cent if a thorough energy makeover was included whenever homes underwent major refurbishment, when the extra costs and disruption of the energy measures would be marginal. Again, all that's needed to make it happen is a bit of regulatory will and muscle.
Transport, the other consumer-driven cause of climate change, looks harder. Shops, employers and amenities seek sites with good parking because the users they want prefer to come by car. This disperses and fragments them, so people need to make complicated criss-cross journeys at specific times to get from one commitment to the next. These are often too far to cycle or walk, and too sparse to be serviced by public transport. So people drive and the shops and businesses build bigger car parks. And move further out to do so. And so on.
This vicious circle is more intractable than the housing one because any single intervention is thwarted or negated by other parts of the problem. Outside major urban hubs, what most people now regard as normal life is difficult, if not impossible, without a car. And that makes serious restrictions on car use politically impossible.
It doesn't have to be like this. Many Continental cities prove that amenities concentrated together in compact, walkable town centres which have good public transport servicing them and car restrictions in place can form a mutually reinforcing virtuous circle that delivers both a better quality of life and lower carbon emissions. We could flip our vicious circle into the continental virtuous one if we coordinated multiple interventions: a more proactive and coercive planning regime to make major trip-generators move back to town centres; funding inner-city schools and hospitals so they are the best in the land; and better public transport coupled with serious car restraint.
Would the public tolerate such sweeping intervention? Most politicians assume not, to the extent of desperately contorting themselves to avoid admitting the blindingly obvious fact that climate change means that air travel can't keep expanding indefinitely. But two straws in the wind give me some hope. First, London's congestion charge, one of the very few serious pro-sustainability interventions of recent years, not only got Ken Livingstone re-elected but made new Labour gag down its loathing of him to avoid a second electoral humiliation. Second, a friend (braver than me!) recently carried out a scratch opinion survey among the other people queuing for easyJet flights. Most said they thought the fares were ridiculously low and couldn't last, but that while they were available it would be silly not to take advantage of them. Thus they had no trouble distinguishing sensible, individual action to exploit available opportunities from the question of whether those opportunities ought to be available - the distinction between individual and collective choice that new Labour's besottedness with individual market choice suppresses, but which ought to define what politics and government should be about.
Energy security through more intelligent energy use is precisely the kind of collective-action problem that politics and government exist to tackle. There isn't an energy supply gap, and therefore we don't have to contemplate nuclear power to fill it. There is only a gap of political courage and imagination.
Read more from the New Statesman 'Heat and Light' energy supplement at