A vegetarian lays out the economic realities and environmental impacts of “sustainable” agriculture.
For all the strengths of these alternatives, however, they’re ultimately a poor substitute for industrial production. Although these smaller systems appear to be environmentally sustainable, considerable evidence suggests otherwise.
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.
The issue is scale - we can’t have 100 million small farms for each household, and industrial agriculture is the only reasonable, viable, and therefore sustainable answer to human food needs. (Pretty please, before you send me angry msgs, I kindly ask you to read FAO’s “Ethical Issues in Food” and UM’s “Ethical Issues in Farming“(PDF). At least skim them, and think in terms of “scale.” Arguments for ethical treatment of ag animals are great. But the case for ethical treatment is not strong enough to eliminate the need for industrial scale farming).