Desertification, a Worldwide Phenomenon that Consumes Arable Land, Threatens the World Food Supply
Dust storms, sand dunes and waterless desolation. For most people, these images conjure up the trackless, timeless desert. Photojournalist Steven Bryan describes his recent encounter with a sandstorm in the Sahara this way: “Sand whirled around me, stinging my face and eyes. The faster it blew the more encrusted it became in my nostrils and throat. I felt sure I would die by drowning.”
This deluge of sand is common in arid regions such as the Sahara and Arabian Deserts. What is uncommon, however, is to find these conditions spreading worldwide in desert margins, in a new kind of desert, a desert made by humans. This “new desert” is devouring more than 20,000 square miles worldwide every year, and putting another 70,000 square miles at serious risk.
The process is called desertification. The outcome is loss of arable land, with devastating implications for the world’s food supply.
The United Nations’ definition of “desertification” is: “Land degradation in arid, and semiarid, and dry subhumid areas resulting mainly from adverse human impact.” Human misery defines it as 5.7 million people who had seen their once-fertile lands dry up by 1977. By 1984, as many as 13.5 million people worldwide were displaced from the land. Moving along with that growing loss is increasing world hunger: Every day, about 33,000 people will quietly starve to death.
The causes of desertification in the Third World include overgrazing, deforestation and the immense foreign debt of these countries, which leads to overproduction and the abandonment of sustainable practices.
Professor Charles F. Hutchinson, director of the Arizona Remote Sensing Center and Professor of Arid Lands at the University of Arizona, thinks desertification follows from over-exploitation of resources driven by desperation. “Heavy exploitation of range and wood resources usually has an economic origin,” he says.
Indebted nations encourage herders to intensify their operations, says Hutchinson. This usually leads to overproduction, causing prices to fall and rendering the herders helpless to the same dilemma—they put more animals on the land to try and erase their debt. The animals eat everything in sight; the vegetation vanishes, and the topsoil which held the vegetation in place is soon blowing in the wind. With the topsoil gone, so is the hope for yielding crops.
Dr. Neil Redford, professor of geology and geophysics at the University of Leicester in England, believes poor land management is to blame. “Whether or not desertification occurs depends upon the nature of resource allocation in the dryland regions,” he says.
The problem is worldwide. Nearly 70 countries are affected. If soil erosion and desertification continue at current rates, says the United Nations, 185 million acres of the world’s arable land will be taken out of production between 1975 and the year 2000.
Does climate change cause desertification? Or does desertification change climate? Professor Hutchinson says the evidence is inconclusive. “They’ve been looking for a signal that would relate land use and climate at a regional scale for the last 20 years, and they haven’t succeeded. The climate connection is probably not as pronounced as people might think.” But, Hutchinson adds, studies done along the U.S./Mexico border have shown something different.
“We recorded higher temperatures on the Mexican side, where the resources were being exploited more intensively, than on the American side,” Hutchinson says. “But the kind of long-term effects that process might have are not clear. Whether farming methods influence precipitation or any other factor in the local water balances is certainly up for debate.”
Some researchers believe a potential warming of the atmosphere is a major concern, as well as human overexploitation of fragile landscapes, a process that could initiate or even reinforce climatic changes, strengthening and extending the problem.
Professor Hutchinson is pessimistic that unless economic pressures are relieved, “It’s unlikely that you can have any significant effect on the resource.” But a more optimistic Dr. Redford sees a variety of steps that can be taken: “By applying rather simple technologies, such as soil conservation methods and reforestation, along with developing shallow groundwater resources, land degradation may yet be halted.”
However, is stopping desertification in its tracks going to be enough? James Gustave Speth, administrator of the United Nations Development Program, thinks that’s too modest a goal. “We must not merely halt desertification, we must reverse desertification,” he says, “and develop successful programs to regenerate the environment.”
The United Nations Environment Program (UNEP) estimates that the welfare of up to 900 million persons may be in jeopardy from desertification. Representatives of 87 nations signed a convention in Paris in October 1994, hoping to reverse the situation. This document, first proposed at the June 1992 Earth Summit in Rio de Janeiro, will become an international treaty when ratified by 50 of these countries (37 have ratified it so far). The proposed treaty would work to channel “substantial” additional funds into protecting the fertility of arid lands.
Still, some scientists question whether desertification is a real phenomenon. They point out that deserts are constantly expanding and contracting somewhat, as satellite images reveal, but that the boundaries usually oscillate within fairly well-defined ranges.
Dr. Redford admits that great sand migrations are a fact of life, but he adds, “Desertification of drylands on desert margins is much more deceptive. It preys on hunger-stricken populations and leads to the land degradation cycle.” And more proof of humanity’s increasing strain on the Earth.