Landmark #1: Population
My grandmother, Lillian Cottrell Deibert, lived to see most of the twentieth century. See was born in 1900 and died in 1996, and she lived almost all her life in Marshall County, Kansas where she ran a small family farm. Year after year the soil on her farm gave rise to tens of thousands of pounds of wheat, milo, and soybeans. My grandparents and their farming partners conscientiously guarded the soil against erosion. Without topsoil, the land would no longer be a prolific source of food.
When my grandmother was born in 1900, there were about 1.6 billion people on the face of the planet. Today there are more than three and half times as many, around 6 billion. (About 5.8 billion in 1996, 5.9 billion in 1997, and 6.0 billion in 1998, according to 1994 United Nations predictions.)
When my grandmother was born, the earth probably had over 6,000 billion tons of cropland topsoil, which averaged out to about 4,000 tons per person. Today the earth probably has less than 5,000 billion tons of cropland topsoil, which averages out to maybe 800 or 900 tons per person. Every year we're losing more topsoil to erosion, contamination, desertification, and urbanization.
In recent years the population has been growing by about 93 million people per year, while soil erosion claims an estimated 24 billion tons of topsoil from our farmland. We have every reason to expect that for the rest of this decade there will be increases in both the rate of population growth and the rate of topsoil loss. What happens in the next decade will depend greatly on what you and I do this decade.
"The soil is the one indestructible, immutable asset that the nation possesses. It is the one resource that cannot be exhausted; that cannot be used up."
-- the U.S. Bureau of Soils, 1909
"If you think what exists today is permanent and forever true, you inevitably get your head handed to you."
-- John Reed, Chairman of Citicorp
So what's the problem here -- too little topsoil, or too many people? Well, right now, neither. For now, we have enough topsoil per person. The problem is trends -- topsoil is declining rapidly and population is growing exponentially. Topsoil loss is serious, but it's population growth that accounts for the majority of this century's dramatic fall in topsoil per person.
The topsoil situation is alarming, but I don't think that we'll ever run out of topsoil. As we begin to run recklessly short of topsoil we'll take two simple steps to adapt -- we'll stop having as many children, and we'll get more serious about soil conservation. Early advocates of these two behaviors will help to smooth the transition.
| Exercise | Run an experiment. Conceive a child today.
Wait patiently. When your child is 50, see whether the
world supply of topsoil is still sufficient to feed the
world supply of people. Alternatively, before deciding to conceive a child, take a month off from work to analyze the state of the world. Write a report summarizing your estimate of probable living conditions during your child's lifetime. |
The Bottom Line
Topsoil per person is one vital sign that can be a useful
indicator of the state of the world. Every high school graduate
should have an idea of how much there is and how fast it's going.
