For though we may be the Earth's gardeners, we are also its weeds. And we won't get anywhere until we come to terms with this crucial ambiguity about our role - that we are at once the problem and the only possible solution to the problem.

There are certain products that it's worth buying organic just because the alternatives have so much pesticide. There's a list of the dirty dozen that you can get off the Web. Strawberries, potatoes. A handful of crops that have very high pesticide residues if you don't buy organic. If you eat that a lot, that's a good place to invest.

Meat is a tremendous environmental challenge. It contributes enormous amounts of greenhouse gas, especially beef eating.

For we would no longer need any reminding that however we choose to feed ourselves, we eat by the grace of nature, not industry, and what we're eating is never anything more or less than the body of the world.

Imagine for a moment if we once again knew, strictly as a matter of course, these few unremarkable things: What it is we're eating. Where it came from. How it found its way to our table. And what, in a true accounting, it really cost.

We could have a greener economy, even a greener consumer economy by changing the rules - whether it's by taxing carbon or trading carbon, I'm not sure what - but in the end there's just a fundamental problem with the sheer amount we're consuming.

The sheer novelty and glamor of the Western diet, with its seventeen thousand new food products every year and the marketing power - thirty-two billion dollars a year - used to sell us those products, has overwhelmed the force of tradition and left us where we now find ourselves: relying on science and journalism and government and marketing to help us decide what to eat.