It's environment week at Oxford Brookes University. On Wednesday evening I took an evening off from campaigning to attend a lecture/discussion led by Bill Dunster, architect of BedZED, Professor (and Lib Dem City Councillor here in Oxford) Sue Roaf, and others entitled "Designs on the Planet".

It was a debate about how we're all facing an energy crisis in the not too distant future and how we need to build our homes, workplaces and communities to survive only on the energy we can generate ourselves as a nation from sustainable resources - something around 10% of the copious energy we fritter away today.

The media is in a frenzy about politicians "going green" by example, or not, with Ming Campbell selling, or not, his Jaguar, Dave Cameron choosing a hybrid Lexus and forcing his environment spokesperson to get rid of the Porsche, how well your local council does on recycling and so on. We have a hose pipe ban about to be extended to teeth cleaning it seems. Soon we will be advised to drink our pee to save water no doubt.

I've said it before, but it bears saying again, if the "mainstream", and especially those who used to be quite eco-sceptical, have seen the (energy efficient) light and are now promoting action to deal with or adapt to climate change, then perhaps the first battle of the "War on Weather" is being won, but the changes that are being suggested vary wildly. The "are you doing your part" sort of message of the politicians - flogging the gas guzzlers and switching off the TV - is, according to Dunster, Roaf and others fiddling while Rome burns.

And their prognosis is, I think it is a fair word to use, cataclysmic, unless we embrace huge changes. Huge, costly (in financial terms) changes.

All of them are missing the point. They are all dealing only in symptoms and adjusting to the effects of something that we can in fact change very little. For many, the damage is already done. We may be able to slow it down. The most benign interpretations may even suggest that we can do things now that will cause changes for the better, in time. But let's face it, the planet is a vast system - talk about how long it takes to turn a supertanker around and multiply it by hundreds, maybe thousands of years.

Yes, as one well known notso-eco-organisation says "every little helps", but it's not addressing the root of the problem. Everyone feels a bit better for doing their bit, I'm sure. But we are fighting a losing battle.

However, there is one system that forces us into the sort of habits that we generally now seem to accept have helped cause the problems on the horizon. A system created by human ingenuity rather than an immutable law of nature. A system that has changed and adapted, often out of all recognition, from time to time as human needs have changed. A system that, unlike gaia, the great mother-ship, whatever you want to call our one and only home planet, can be changed "merely" with an act of political will.

IT'S THE ECONOMY STUPID

I say "merely" because of course there are huge vested interests involved. The 0.25% of the world's population that own more than the other 99.75% put together will of course find a way to survive any impending crisis. It will not be the financial elite that will disappear under the water as it rises over Battery Park or Belgravia but the poor, just as it was with those worst affected by the Boxing Day Tsunami sixteen months ago.

And the not so poor. Just those who, despite years of hard work, saving to buy their dream home, cannot afford simply to up sticks and move to higher ground. In fact, most of us. The same most of us who have begun to recognise that the way we treat the environment has to change. The vast majority. Crucially too, in case you don't think this applies to you, it's the same most of us who are now worried about whether we will be able to retire on a decent pension any time soon, because the reasons are the same.

But this is not an envy-trip. I don't begrudge people who have played the system successfully what they have gained (so long as they have played fair) - it is the system that now needs changing. The rules of the game, as Tony Blair said about another war he's losing.

What we have to ask ourselves now is whether we can afford not to do whatever it takes, to change whatever we can actually change, in the faint hope of changing the prognosis for the planet but in the better hope of being able to survive the changes that may already be inevitable. And the things that are ripe for changing are the man made systems and rules that say, in particular "we, the vast majority, can't afford to..."

So stop fiddling, and take the initiative. The mass movement that's building of concern for our planet and our future, from all shades of the political spectrum can achieve it. Do we want to fry merely for want of looking at other economic models that promise "sustainable abundance"? For fear of upsetting an economic "orthodoxy" that has pushed us into this position. It has served us well, arguably. But it is now, more than anything else, a hinderance and not a help. At least for about 99.75% of us.

"Why should we be beggars with the ballot in our hands?"