Over a month ago, Reuters issued a widely-mentioned (but not widely discussed) press release on soils.“Only 60 years of farming left if soil degradation continues,” reads the release. It quotes some United Nations officials, warning of the problems of soil erosion.
Is anyone paying attention? In an ideal world, the public would be outraged by this. Congressional committees would study the problem. Students would demand courses on soil preservation. But back in the real world, farmland just isn’t that big of a deal. After all, agriculture is just a very small part of the U. S. economy. We could also debate whether this is an exaggeration. Perhaps we have 100, or even 200 years of farming left!
This kind of blindness to an obvious issue demands comment. Without oil, it’s back to the horse and buggy, I suppose. But without farmland, it’s back to — what? Hunting and gathering? Hunting and gathering would support humanity only if population were reduced by about 99.9%. Soil is the basis of all life. Suppose that scientists announced that a giant asteroid was going to hit the earth 60 years from now, annihilating 99.9% of the human race. We’d be paying attention.
Distinguished ecologist David Pimentel and others have warned that soil is eroding many times faster than it is being formed. To form an inch of topsoil takes centuries; but soil erosion is progressing many times faster than that. In the United States, soil is eroding at about the rate of 10 tons / hectare / year (1 hectare = 2.47 acres). However, soil is formed only at about a rate of ½ to 1 ton / hectare / year, so soil erosion is 10–20 times greater than soil formation. In Asia and Africa, the rate of erosion is even greater, on the order of 30 to 80 times greater than the rate of soil formation. This is patently unsustainable.
Food is a complex topic. We could go to organic farming, and that would help preserve the soil. But it isn’t clear (to me, at least) that organic farming would scale up enough to feed the world. The yields per acre for organic versus conventional agriculture are comparable, but maintaining soil fertility would become an issue. Right now, artificial fertilizers provide a lot of soil fertility, and to compensate for the “loss” of the artificial fertilizers, you would need additional land in some form — either to grow plant manures, to support animals that would provide manure, to remain fallow, or to grow a cover crop. “No-till” agriculture is highly mechanized and requires extra herbicides — definitely not an “organic” alternative. On the other hand, conventional agriculture is quite destructive to the soil, so none of our choices are good.
We don’t face a shortage of this or that; we are generally facing the limits to growth. Ballpark, back-of-the-envelope calculations seem to indicate that a sustainable agriculture would require that the entire world go vegan and that we reduce the human population by about 80%. Vegans need to understand how serious our environmental situation is; people just have no idea of the extent to which humans have overrun the earth and vastly overshot their resources. There is hope for the future, but we need to radically rethink our whole approach to the economy and nature.