Peak oil is the point at which the world has used up half its supply of oil. Depending upon who is telling the story, the globe has already passed peak oil, is about to pass the half-way point, or there’s nothing to be concerned about. The optimists in the last group say there are plenty of energy alternatives to switch to once the oil is gone.
But, “peak soil” is another matter; topsoil is disappearing and there’s nothing to replace it.
Making Soil is a Slow Process
Creating soil is a slow process. It starts with sand, grit, and river silt. Add in the remains of a few hardy plants that manage to get a toehold in the crumbled matter. Animal excrement and their decaying bodies when they die increase the richness and fertility.
Writing for the Peak Generation blog (May 12, 2010) Matthew Wild points out “It takes tens of thousands of years to make 15 centimetres of topsoil, about six inches’ worth.”
Farming Disturbs Soil Ecology
Protected by tree cover, tough prairie-type grasses, or other native vegetation, the world’s early supply of topsoil was relatively stable. Then, humans developed agriculture and the trees were felled and the grasses ploughed in.
As long as there were only a few million people on the planet, there was plenty of soil to go around. But, industrial farming and logging has exposed soil to wind erosion and desertification; a process that is accelerating with global warming. The pressure on soils has reached the point to where, writes Wild, “The world is losing soil 10 to 20 times faster than it is replenishing it.”
More Mouths to Feed from Less Land
At the same time, the world’s population continues to grow, with the United Nations projecting a global population of 9.3 billion in 2050; up from 6.8 billion today.
In a May/June 2010 article in Mother Jones entitled “The Last Taboo,” Julia Whitty quotes geomorphologist David Montgomery, author of the 2007 book Dirt: The Erosion of Civilizations: “Just when we need more soil to feed the 10 billion people of the future, we’ll actually have less—only a quarter of an acre of cropland per person in 2050, versus the half-acre we use today on the most efficient farms.”
The Hope of the Green Revolution
The American agronomist Norman Borlaug was showered with honours, including the 1970 Nobel Peace Prize, for his work in developing what came to be called The Green Revolution. In the 1960s, his techniques promised to free the world’s poorest people from famine.
In developing countries such as India, Pakistan, and Mexico, Borlaug introduced, as an obituary recorded after his death in September 2009, “a combination of modern agricultural production techniques and his new high-yield wheat varieties.
“As a result, Mexico became a net exporter of wheat by 1963. Between 1965 and 1970, wheat yields nearly doubled in Pakistan and India, greatly improving the food security in the subcontinent.”
Other Resource Shortages Undermine Farming
The Green Revolution requires extensive hydrocarbon and chemical inputs in the form of artificial fertilizers, pesticides, herbicides, and the wide use of irrigation. But, world supplies of the source stocks for these farming aids are running out, and water is a seriously depleted resource almost everywhere.
Recognizing this problem, scientists are working on ways of creating new soil. According to the article “Scientists Focus on Making Better Soil to Help with Food Concerns,” by Drake Bennett (New York Times, April 29, 2008) “Scientists in Australia and the United States have started making rich new earth from industrial waste, and research into the astonishing fertility of a mysterious Amazonian soil may lead to an additive that can boost the power of soil for thousands of years.”
Rupert Taylor - Rupert Taylor is the editor of a magazine that provides background to current events.
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