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CHAPTER 5

Human Populations

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The challenges faced by the people of Bangladesh dramatically demonstrate issues arising from a population growing beyond the capacity of its environment to support them.

Tink. Tink. Tink. This is the sound of monsoon rains pinging against the tin roof of a shack in Bangladesh. Imagine, for a moment, that this is where you grew up: Each night you sleep on the dirt floor, squeezed into the same tiny room with four or five other members of your family. Your entire home is about 100 square feet in size, 25 times smaller than a typical American home. When your mother cooks on the wood-burning stove, choking black smoke fills the house. You make do with just 10 liters of water per day for both your washing and drinking water. By comparison, the average American uses 380 liters each day. One of your siblings has diarrhea, another hunger pangs.

Life in Bangladesh, one the world’s most densely populated countries, is not easy. Nearly 150 million people live on this flood-prone river delta between India and Burma, a region about the size of Iowa. Today, the country is notorious for having some of the most poorly paid workers, who labor under harsh conditions at garment factories that produce clothing for international companies such as Benetton and Walmart. In April 2013 an eight-story factory collapsed, killing 1,129 workers and injuring more than 2,500. For people who live in dire poverty and need to feed their families, such jobs are the only option they have.

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“The key problem facing humanity in the coming [21st] century is how to bring a better quality of life—for 8 billion or more people—without wrecking the environment entirely in the attempt.”

Edward O. Wilson, distinguished ecologist

Sadly, their options will only get worse as Bangladesh’s population continues to expand. Researchers estimate that population will reach 218 million by the middle of this century, with most residents living in slums, lacking proper sewage disposal and electricity. The country hasn’t produced enough food for its people since the 1950s, and agricultural land has only declined since, replaced by living spaces. By 2060 there may be none left at all.

Bangladesh’s struggles provide a cautionary tale for the wider world. Prior to the Industrial Revolution, the human population on Earth numbered less than 1 billion. It has soared over the last 200 years. Halloween day of 2011 was a particularly frightening day for environmental scientists interested in demography, the study of the statistics of human populations. The United Nations christened it the “Day of Seven Billion,” when the world’s population crossed that threshold. “Our world is one of terrible contradictions,” Ban Ki-moon, the UN secretary-general, said at a news conference. “Plenty of food, but one billion people go hungry. Lavish lifestyles for a few, but poverty for too many others.”

Rich or poor, these 7 billion bodies require food, water, and other natural resources to build their homes and feed their families. Not only does this place a heavy toll on the functioning of natural ecosystems and our global economy, but many environmental scientists believe that the resources we depend on are running out. The richest may see their quality of life decline, while the poorest among us have little hope. The World Wildlife Fund’s Living Planet Report predicts that, if present trends continue, by 2050 the productive capacity of nearly three Earths will be needed to meet the needs of the world’s 8 to 11 billion residents (see Chapter 1, page 20). It’s a problem that ecologist Paul Ehrlich famously called the “population bomb,” and population growth represents one of the most fundamental challenges when it comes to balancing human rights and environmental sustainability.

Central Question

How can we achieve sustainable human populations?