It's not just a problem of animal production (meat, dairy, eggs) but the intensive mode of production, and the integration of crops into the process -- practically speaking, the maize (corn) and soy system is almost entirely (bar biofuel use) pointed at intensive poultry, pork, beef and dairy production. So we have a top-heavy system of factory farming (batteries, feed-lots) and a great deal of arable land dedicated to industrial inputs into that system. The outcomes are pollution by the different industrial stages of the process, and poor-quality but "cheap" products.

Compare this to a system where animal production is extensive (using grasslands and marginal lands) and less arable is used for "intensifying" inputs like maize and soy. There'd be a lot less pollution, and better-quality products. There'd also be a lot less in terms of quantity, and the price would be higher. Personally, that's the way I think things should go. Eating less, but better-quality and more expensive, animal products is fine by me, it's what I do.

However, the mass marketing of "cheap" factory-farm products has an appeal that (though it is easy to argue against) is hard to persuade against. In almost all human cultures, eating meat has a festive aspect, and when people can get meat cheaply they go for it. Eating vegetables and cereals appears humdrum by comparison and above all confers no prestige: you're "eating spaghetti" (or rice, or bread, or potatoes) meaning you're too poor to do better. Having meat on the table daily means you're doing well. The mythology is more important than the reality (of the nutritional quality of the intake, of the environmental problems caused).

So there's rising demand for meat in emerging economies where urban populations are seeing average incomes rise. And, to accompany this, the growth of environment-unconscious factory farming. And who are we in the developed world, who invented the intensive production techniques used and have had more than our fair share of glutting on meat, to stop them?

We might at least change our own consumption and production to show that things can be done differently, but we're still a long way from that. Intensivist-productivist methods are in fact gaining ground, with the introduction of GM crops in particular -- backed by the argument that we have to "feed the world". (Read: feed intensive animal production).

What may seem obvious to us doesn't appear so to the vast majority, and the commercial forces are formidable. Things don't look too hopeful.