Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

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number political refugees, are an emerging global concern. People may
endure temporary droughts, but desertification forces emigration once the
land can no longer sustain either grazing or farming.
Desertification is not just happening in Africa. More than a tenth of
Earth’s land area is desertifying—about a third of the planet’s dry lands.
Studies over the past fifty years report a pace of desertification in regions
with between 5 and 20 inches of annual rainfall that, if continued, would
desertify most of the entire semiarid zone in this century. A decade ago, at
the 1996 World Food Summit in Rome, global protection and sustainable
management of soil were emphasized as critical for the security of future
generations.
Before the Second World War, western Europe was the world’s only
grain-importing region. Latin American grain exports were nearly double
those from North America in the late 1930s. Exports from the Soviet
Union’s virgin lands were comparable to those from North America’s Great
Plains. Self-sufficient before the Second World War, Asia, Latin America,
eastern Europe, and Africa all now import grain. By the early 1980s over a
hundred countries relied on North American grain. Today North America,
Australia, and New Zealand are the world’s only major grain exporters.
Famine returned to the global scene after decades of unprecedented
prosperity in the postwar years when highly variable rainfall, coupled with
increasingly severe land degradation, led to regional crop failures. In the
mid-1960s, the United States shipped 20 percent of its wheat crop to India
to prevent famine from two consecutive crop failures. When Indian crops
failed again in 1972, more than eight hundred thousand Indians starved to
death. This time there was no American bailout; increased Soviet imports
had tied up available wheat supplies. In addition, the 1972 Russian grain
purchase encouraged U.S. farmers to plow up marginal land, undermining
decades of soil conservation efforts. Today the impact of regional crop
failures on global grain prices reflects the close balance between world food
supplies and demand. The ongoing availability of surplus North American
crops is an issue of global security.
Worldwide, over two billion acres of virgin land have been plowed and
brought into agricultural use since 1860. Until the last decades of the twentieth
century, clearing new land compensated for loss of agricultural land.
In the 1980s the total amount of land under cultivation began declining for
the first time since farming reached the land between the Tigris and
Euphrates. In the developed world, the rate at which new (and generally
marginal) land was brought under cultivation fell below the rate at which
dust blow