We have about 6.8 billion people on a tiny orb only 8,000 miles wide and 24,000 miles in circumference that we call Earth. We add about a million and half people to our world population every week! How have we reached the point that many describe as global overpopulation? What is our Planet’s carrying capacity? Is zero population growth desirable, or attainable? What are the causes and effects of human overpopulation?
The family of humans, known as the hominids, has populated Earth, according to the fossil record, for 5 to 6 million years. The hominids transitioned from one genus to another before our genus, homo, appeared about a million and half to two million years ago. We transitioned through a number of homo species before our species, homo sapiens (“sensible humans”) emerged about 150,000 years ago.
For the 5 to 6 million years we hominids have been here (Earth has been here for 4.56 billion years in a universe that has been here 13.7 billion years), we have mostly been Stone Age hunters and gatherers. For the 150,000 years we modern humans have been here, we too have mostly been hunters and gatherers. About 12,000 years ago, with the domestication of plants and animals, our Agrarian Age began. Since then, we’ve mostly been agrarians. A little more than 200 years ago, in the late 1700s, the Industrial Age began in England. By 1850, it spread to Belgium, Germany, France and the United States. Over time, it spread to other industrial countries. About sixty years ago, we transitioned from the Industrial Age to the post-Industrial High Tech Information Age we live in today. It is an age that allows us to disseminate information almost anywhere instantly.
Over time, we accumulated people. Two-thousand years ago, our population was at 250 million. In the year 500 A.D., it remained the same. By 1000 A.D., we climbed to 500 million people. We reached 750 million people around 1500 A.D. We hit our first billion mark in 1800 at which time the Industrial Revolution kicked in. We added people more rapidly and began to move quickly in the direction of human overpopulation. Between 1800 and 1900 we added 600 million people. At 1900, we were at 1.6 billion. By 1960, in 60 short years, we nearly doubled that as we reached 3 billion.
In 1960, we humans had been here about 150,000 years. It took us that long to accumulate 3 billion people. How long did it take for us to double that number? Thirty-nine years! In 1999, we reached 6 billion people. It is estimated that we will be at 9.2 billion by 2050. This is an exponential increase in birth rate, leading to questions concerning Earth’s carrying capacity.
The effects of human overpopulation are multiple and ominous. As birth rates climb, natural resources get used up faster than they can be replaced, creating enormous economic pressures at home while the standard of living plummets throughout the rest of the world. As the result of having so many people who do not understand our reality and its behavioral demands, we have created an interrelated web of global environmental problems. We are depleting our natural resources: our forests, fisheries, range lands, croplands, and plant and animal species. We are destroying the biological diversity on which evolution thrives (this is being called the sixth great wave of extinction in the history of life on earth, different from the others in that it is caused not by external events, but by us).
With powerful new electrical and diesel pumping techniques, we are draining our aquifers and lowering our water tables. We are systemically polluting our air, water, and soil, and consequently our food chain. We are depleting the stratospheric ozone that shields us from harmful ultraviolet radiation. And, we are experiencing symptoms of global warming: heat waves, devastating droughts, dying forests, accelerated species extinction, dying coral reefs, melting glaciers, rising sea levels, more frequent and intense storms, and a more rapid spread of diseases.
What is the solution for global overpopulation? What must we do to ensure that population growth is not out of control? The answer lies in education. We humans are a very young species. We have been here for only a short time. We are like a child just learning to walk. We face grave challenges that demand a rapid shift in our behavior. Our teacher is our parent. Our parent is the natural world from which we emerged. In every way, in every facet of our existence, we must learn to align ourselves with that which supports life. There is no alternative if we are going to avoid catastrophic consequences.
With so many of us on a very small planet, and with the addition of so many more every week, we can no longer continue to relate to each other, our environment, ecological systems and biosphere as we have or we will succumb to the effects of human overpopulation. Nature, which could not care less, will eliminate us. We humans must grow up and learn to walk…hand in hand with each other and with our natural world. There is no alternative if we wish to sustain humanity and advance our civilization.