Al Gore, presenting Prince Charles with a Harvard University award for raising environmental awareness, may have felt a little green himself - with envy. Not because of the award; after all, Al won it last year. Nor because of the attention. With the new, unbuttoned movie-star/guru-wonk/presidential-candidate-tease thing that Al's got going, his face is rarely off the front pages.
No, it was the motorcade. While Al probably got a cab, Charles' convoy - at least at one stage of his trip - comprised six limos, two SUVs and many police cars. And that's after he got off the plane (a transatlantic flight adds 1.5 tonnes of carbon per passenger to the atmosphere).
As part of his lecture-circuit patter, Gore tells a good joke about driving along the highway with his wife Tipper, and looking in the rear-view mirror to see... to see, well, nothing. 'You know how people who have lost an arm or a leg describe missing limb syndrome? Well, have you heard of missing motorcade syndrome?'
That's the thing about democracy. While Charles just has to potter around, chatting to the plants until Mum pops off, poor Al had to submit to the wisdom of the people, who sagely selected George Bush. It's now, of course, a daily sport to catch out politicians or environmentalists: David Cameron's car follows his bike, Prescott gets in his Jag to drive a few hundred yards, Charles flies to get his green gong. Public figures live in fear of being caught in a carbon-fuelled clinch.
But the hard fact is that environmental damage is inherent in the structure of modern societies. The way politics is done, the shape of the media market, the demands of international business, and the way we shop all harm the planet. Peccavimus - we have all sinned. This is not to say that moves made by the likes of Marks & Spencer, Tesco and Wal-Mart are not to be loudly applauded. They have given the notion of corporate social responsibility a new resonance - especially M&S's pledge to go carbon-neutral by 2012. But it is to say that such moves are insufficient. The superstores can no longer be accused of fiddling while Rome burns, but nor are their actions enough to douse the flames.
If we are serious about climate change (and that is a big if), we have to go for the belly of the capitalist beast. If rates of consumption continue to rise, then the very best efforts of the corporates will do little more than hold emissions at the current level. We'll be running to stand still. One of the most common cliches of the current debate about climate change is that it is hardly worth bothering to buy a milk float masquerading as a car when China builds a new coal-fired power station every five minutes. (It might be days. Whatever.) It is true that China's economy is booming, and that it is growing in a dirty, polluting fashion. But here's the question: who is buying all the goods being produced in China's dirty factories? Where's the demand coming from? And here's the answer: you and me.
Wal-Mart has recently announced that the energy used in its stores will be sourced from renewable suppliers. This is a wonderful piece of news. But Wal-Mart's real environmental impact is not in Georgia but in Guangdong. It buys so many Chinese products that if it were a nation, it would be China's sixth-largest export market.
Cheap manufactured goods are being sucked out of China by Western consumers who drive to the shops to buy them, and then use the dirty Chinese as an excuse not to bother with the recycling. There's a real question about the seriousness of each of us, as individuals, when it comes to the environment. Of course, we tell pollsters that we care. That is because we want them to like us. But when it comes to paying extra, or waiting longer, or working harder, our green halo slips. The markets for green energy, sustainably sourced products and electric cars remain tiny. And in the end, we get what we pay for.
Perhaps the fears about environmental destruction tap into a deep-seated psychological need for a bogeyman of one sort or another. As Frank Kermode suggests in his 1967 book The Sense of an Ending, each generation seems to need to choose its own Armageddon, from fascism to communism to nuclear war. And now, perhaps, to the environmental catastrophe portrayed in the 2004 film The Day After Tomorrow, with the same realism as all Hollywood disaster movies. But how many people came out of the cinema vowing to boycott all food that has been flown into Britain? How many swapped their Beemer for a bike? Climate change in this context is rather like the shark in Jaws: it scares us for an hour, but doesn't stop us going fishing afterwards.
The great irony about the recent moves by the supermarkets is that they seem to be more green than us. After years of guff about how 'ethical consumers' were going to start using their muscle to force companies to behave better, it seems that some firms have given up waiting and decided to clean up their act anyway. It is ethical CEOs, not ethical consumers, that are in the driving seat. But there are limits to what they can achieve. Capitalism drives costs down and demand up. That is what it does. But in the end, it derives its dynamism from the consumer. And, of course, the whole world is capitalist now. The future of the environment depends on what kind of capitalist each one of us chooses to be today.