Human overpopulation is an animal rights issue as well as an environmental issue and a human rights issue. Human activities, including mining, transportation, pollution, agriculture, development, and logging, take habitat away from wild animals as well as kill animals directly. These activities also contribute to climate change, which threatens even the most remote wild habitats on this planet and our own survival.
According to a survey of the faculty at the SUNY College of Environmental Science and Forestry in April of 2009, overpopulation is the world’s worst environmental problem. Dr. Charles A. Hall went so far as to say, “Overpopulation is the only problem.”
How many people are there, and how many will there be?
According to the U.S. Census, there were six billion people in the world in 1999. On October 31, 2011, we hit seven billion. Although growth is slowing, our population continues to grow and will reach nine billion by 2048.
Are there too many humans?
Overpopulation occurs when a population has exceeded its carrying capacity. Carrying capacity is the maximum number of individuals of a species that can exist in a habitat indefinitely without threatening other species in that habitat. It would be difficult to argue that humans are not threatening other species.Paul Ehrlich and Anne Ehrlich, authors of “The Population Explosion,” (Buy Direct) explain:
The entire planet and virtually every nation is already vastly overpopulated. Africa is overpopulated now because, among other indications, its soils and forests are rapidly being depleted—and that implies that its carrying capacity for human beings will be lower in the future than it is now. The United States is overpopulated because it is depleting its soil and water resources and contributing mightily to the destruction of global environmental systems. Europe, Japan, the Soviet Union, and other rich nations are overpopulated because of their massive contributions to the carbon dioxide buildup in the atmosphere, among many other reasons.
More than 80% of the world’s old growth forests have been destroyed, wetlands are being drained for real estate development, and demands for biofuels take much-needed arable land away from crop production.
Life on earth is currently experiencing its sixth major extinction, and we are losing an estimated 30,000 species per year. The most famous major extinction was the fifth one, which occurred about 65 million years ago and wiped out the dinosaurs. The major extinction that we are now facing is the first that is caused not by an asteroid collision or other natural causes, but by a single species - humans.
If we consume less, will we no longer be overpopulated?
Consuming less may be a way for us to live within the carrying capacity of the planet, but as Paul Ehrlich and Anne Ehrlich explain, “Overpopulation is defined by the animals that occupy the turf, behaving as they naturally behave, not by a hypothetical group that might be substituted for them.” We should not use the hope or the plan to reduce our consumption as an argument that humans are not overpopulated.
While reducing our consumption is important, worldwide, per capita energy consumption increased from 1990 to 2005, so the trend does not look good.
Lesson from Easter Island
The effects of human overpopulation have been documented in the history of Easter Island, where a human population with finite resources was nearly wiped out when their consumption increased beyond what the island could sustain. An island once lush with diverse plant and animal species and fertile volcanic soil became nearly uninhabitable 1,300 years later. The population peak on the island has been estimated between 7,000 and 20,000 people. Trees were cut down for firewood, canoes, and wooden sleds for transporting the carved stone heads for which the island is known. Because of deforestation, the islanders lacked the resources necessary to make ropes and seaworthy canoes. Fishing from shore was not as effective as fishing out on the ocean. Also, without canoes, the islanders had nowhere to go. They wiped out sea birds, land birds, lizards and snails. Deforestation also led to erosion, which made it difficult to grow crops. Without adequate food, the population crashed. A rich and complex society that erected now-iconic stone monuments was reduced to living in caves and resorted to cannibalism.
How did they let this happen? Author Jared Diamond speculates:
The forest the islanders depended on for rollers and rope didn't simply disappear one day-it vanished slowly, over decades . . . In the meantime, any islander who tried to warn about the dangers of progressive deforestation would have been overridden by vested interests of carvers, bureaucrats, and chiefs, whose jobs depended on continued deforestation. Our Pacific Northwest loggers are only the latest in a long line of loggers to cry, "Jobs over trees!"