It's been more than two years since historian James McWilliams inspired a post here. This time McWilliams has declared that not only is factory farming unsustainable, but all the small-scale locally-produced meat production niches are unsustainable too:
Grass-grazing cows emit considerably more methane than grain-fed cows. Pastured organic chickens have a 20 percent greater impact on global warming. It requires 2 to 20 acres to raise a cow on grass. If we raised all the cows in the United States on grass (all 100 million of them), cattle would require (using the figure of 10 acres per cow) almost half the country’s land (and this figure excludes space needed for pastured chicken and pigs). A tract of land just larger than France has been carved out of the Brazilian rain forest and turned over to grazing cattle. Nothing about this is sustainable...He also thwarts the claim that these systems are more natural because the animal breeds farmers raise are either far removed from nature or their animal urges and life cycles require interference.
...Rotational grazing works better in theory than in practice. Consider Joel Salatin, the guru of nutrient cycling, who employs chickens to enrich his cows’ grazing lands with nutrients. His plan appears to be impressively eco-correct, until we learn that he feeds his chickens with tens of thousands of pounds a year of imported corn and soy feed. This common practice is an economic necessity. Still, if a farmer isn’t growing his own feed, the nutrients going into the soil have been purloined from another, most likely industrial, farm, thereby undermining the benefits of nutrient cycling.Still, I disagree with his thesis. He takes the position that our current "factory farming" system is unsustainable and the small-scale alternatives are unsustainable, therefore eating meat and animal products is unsustainable.
By that logic, he might as well say that food production can never be sustainable.
The critics of "factory farming" have a history of exaggerations, but suppose they are accurate and we shouldn't produce food on a large scale the way we do now. That's simple enough to fix; we follow agricultural economist William A. Masters suggestion and revamp large-scale food production.
There's nothing preventing us from producing an industrial system for food production that deals with the legitimate problems raised by critics, like run-off and animal welfare. If sustainability is a legitimate hurdle to overcome, then we have to make smart changes. Inefficient, wasteful and expensive small farms are not the solution.