Faced with the evidence, many deniers have started to admit that global warming is real, but argue that humans have little or nothing to do with it.

You would have thought that our first priority would be to ask what the ecologists are finding out, because we have to live within the conditions and principles they define. Instead, we've elevated the economy above ecology.

The fact of the matter is that today, stuff-selling mega-corporations have a huge influence on our daily lives. And because of the competitive nature of our global economy, these corporations are generally only concerned with one thing - the bottom line. That is, maximising profit, regardless of the social or environmental costs.

If we want to move towards a low-polluting, sustainable society, we need to get consumers to think about their purchases.

And that, quite simply, is the issue. We live in a finite world with finite resources. Although it may sometimes seem quite big, earth is really very small - a tiny blue and green oasis of life in a cold universe.

If we continue to set human borders and the economy as our highest priorities, we will never come to grips with the destructiveness of our activities and institutions.

Other things, like capitalism, free enterprise, the economy, currency, the market, are not forces of nature, we invented them. They are not immutable and we can change them.