One planet… seven billion people and growing. What lies ahead can be a fascinating human adventure, or a tragic saga of human frailty and shortsightedness.
(Revised January 24, 2012)
The world’s human population has now reached seven billion individuals, and it came at a continuing record pace. The population explosion of the last 200 years has been astonishingly exponential, especially considering that human civilization has grown by some six billion people since the year 1800… but only by one billion people in the 90,000 years prior.
The day of seven billion arrived on October 31, 2011, according to the United Nations Population Division. We are barely under 12 years into the 21st century and Earth has grown by another billion living human beings. Earth’s population reached six billion in October of 1999. Further, in the twelve years prior to 1999 — since July 11, 1987 — another billion people were added to the planet. In fact, the entire human population is twice today what it was in 1968 when 3.5 billion people populated Earth.
The saga of human evolution can be quite sobering. Without having a major planetary catastrophe to blame — like the Earth-crashing meteor some 65 million years ago that brought the dinosaurs and nearly 80 percent of the world’s living species to extinction — several human species have evolved and died off just in the past two-plus million years leaving only one surviving human species today. With so many people now taking up so many of Earth’s limited resources, does a similar fate await today’s modern humans?
The Rise of Humans
Some 2.2 million years ago, the first confirmed humans appeared on Earth. It was Homo habilis – or “Handy man” — who emerged onto the scene as the inaugural species of the human family Homo, which includes present-day humans. But they are now long gone, having only existed on this planet for just under a million years.
Each of the succeeding species of humans has died off, except for, of course, today’s human species, Homo sapiens. Such extinct species of humans includes the first species of man to walk entirely upright and develop human culture – Homo erectus, and the more popular Neanderthals. Even Homo sapiens idaltu — the most recent ancestor of the modern day human species Homo sapiens – is extinct. All human ancestors are gone today.
The sole surviving humans that now populate the earth are actually a subspecies of modern man, who appeared on Earth some 90,000 years ago, as far as we know. They are known as Homo sapiens sapiens. Today’s humans live in a period called the Holocene epoch, also known as the Age of Man, which began about 10,000 years ago. This current period of geological time is not even a wisp of a thread in the 4.54 billion years since Earth first formed. Aptly defined, Holocene is Greek for “entirely recent.”
Yet today’s human population has exploded like that of no other human predecessor. But even more dramatic is that today’s human population has developed more of the planet in more sophisticated and impactful ways than any other Earth species of any kind that has previously existed.
The most inescapable questions about human population growth today are: Can we sustain such incredible upward growth? Or will we reach a balance in our population where human numbers are stable and human life is sustainable? Could we go the way of our now extinct ancestors?
First Known Population Centers
Cities are synonymous with population centers. Their very purpose is for humans to work together, communicate and create a better way of life for the entire community. It is this advanced form of collaboration that enabled humans to increase their longevity.
Catal Hoyuk in Turkey (also Çatalhöyük) is the first known city to have existed. Here, the remains of that city show a well-organized society that is estimated to have included several thousand people. (Photo: from WordPress)
The appearance of the first cities began to form with the end of the last global glacial melting to the margins we see today. The global climate naturally became more temperate. This change in climate produced conditions that allowed humans to move from the more scavenging and nomadic way of life necessary for individual survival, to a more agriculturally productive society.
Hence, urban areas were built around the premise of people cooperatively growing and cultivating their own food for survival and sharing throughout the community. The benefit of having people within close proximity of each other provided benefits that exceeded the costs of their efforts. Everybody worked and benefited together.
The very first city is known to have developed about 8,000 years ago in Turkey, in the early years of the Holocene period. This city was called Catal Hoyuk (also Çatalhöyük). Its population is estimated to have been in the thousands, certainly making it the most populous city on Earth at the time.
Population Growth
World population began to grow appreciably, albeit very slowly, from the beginning of cities and ultimately their growth into urban centers. Although the present human species has been around for some 200,000 years, cities have been around for less than 5 percent of that time. It is estimated that there were about 2.5 million humans living on the planet soon after cities began to develop, growing to between 170 to 300 million by the first year of the Current Era (1 C.E., traditionally 1 A.D.).
For the next 18 centuries, population growth would continue to climb very sluggishly, although measurably. The human life span would remain challenged by health-defiant living conditions, disease, and natural environmental conditions, from harsh temperature extremes to drought, that would inhibit the human capacity for its greatest growth and reproductive capability. The Black Death by itself wiped out about 100 million people in Europe between 1348 and 1350, reducing the European population by between 30 and 60 percent.
The Root of the Population Boom
The Ecological Impact of the Industrial Revolution - Get the story about the Industrial Revolution’s impact on population and world ecology, in this related article.
Humankind began to see its enormous development capabilities over all other living species begin to take root in the late 18th century with the start of the Industrial Revolution. Since Homo sapiens appeared on this planet 200,000 years ago, world population had grown to just one billion. But it was about to take a dizzying surge upward.
The impact of the Industrial Revolution is at the very root of today’s rampant, if not unbridled, human population growth. Though the Industrial Revolution did not occur overnight, it literally changed humans’ relationship with their environment and showed people how the environment could be exploited for the benefit of human health and quality of living. And the greatest evidence of the effect of the Industrial Revolution on human life is seen in the consequent worldwide population explosion.
Nearly every ecological and environmental concern stems from population growth over the last two centuries, particularly the 20th century. Certainly, natural environmental occurrences such as drought, earthquakes, hurricanes and typhoons, temperature extremes and other such conditions also impact humans, but their consequences on human population have a life-altering domino effect, commensurate with the population size (note the Great East Japan (Fukushima) Earthquake and Tsunami in March 2011).
Essential elements for life, such as food supply and consumption, fresh air, potable water, health and energy, are all directly and significantly affected by the sheer number of humans living on this planet. Human production and other activity have required land, energy, water and forest products, while the use of such products and activity result in wastes, pollutants, loss of natural resources such as forests and fertile, productive land.
When populations were smaller, use of natural resources was naturally manageable… sustainable. But the population explosion of the 20th century — when 4.5 billion people were added to the global populace — took place without regard or foresight for the related after-effects until they became serious problems. Yet, it was during the 20th century that advances in medicine, sanitation and nutrition significantly contributed to increased longevity and a vastly reduced death rate.
Rachel Carson
It wasn’t until 1962 when Rachel Carson published her book, Silent Spring, that people began to notice the correlation between environmental problems and human activity. In this particular case, Carson focused on pesticides showing up in streams, rivers and other natural habitat, creating problems for living species and threatening human health. Even then, such connections were strongly refuted by the very chemical companies that caused the problems; yet the causes and effects were obvious and people slowly came around to understanding we had to do something about it.
The disquieting fact is, in 1962, the world human population was only 3.1 billion — less than half of what it is today.
Still, countries around the world are now trying – in different ways — to find ways to right the ship, while trying to build and maintain healthy societies with healthy economies. But when you look at a country like the United States, which bears only 4.45 percent of the world’s population yet consumes a whopping 25 percent of the world’s resources, it is clear we have a long ways to go. Still, it can be done.
The Significance of Seven Billion
Earth’s city lights show robust population centers throughout the world as would be seen at night from space. Even the Dark Continent of Africa shows robust urbanization in many of its regions. Image: NASA
The Day of Seven Billion is both a celebration and a harbinger of our future. Yes, it is the next billion-person benchmark in population growth that seems to come around more often than the North American cicada returns from underneath the ground to live, breed and die (that is every 13 to 17 years).
But Earth will see eight billion people in 2025, nine billion in 2043 and even ten billion in 2083. If you follow this rate of growth, you will notice that world human population growth is slowing down!
Zero Population Growth
Is the World Headed Toward Zero Population Growth?
Read more about the ZPG trend in our companion article.
Zero population growth (ZPG) is an ideal that has it negatives and positives. On one hand, ZPG means human population growth will reach a state of balance where the number of births will equal the number of deaths and societies can more easily deal with sustainable practices. On the other hand, ZPG has the potential to cause major disruption in economic growth since business in general today relies on continually increased production.
Regardless, human population growth is slowing down. It is difficult to say when, or even if, ZPG will be achieved, but it is headed in that direction. You will be hard-pressed to find an agency that will predict when the world will reach ZPG, but some agencies are saying that human population growth will decline and perhaps reach ZPG toward the end of this century.
Today, some countries have already achieved ZPG, and some are experiencing negative population growth. One ideal out of all of these countries is Germany, which has reached zero population growth and for all practical purposes has a healthy economy relative to the current world standard.
Extinction or Sustainability?
It is likely that whether or not the world human population levels off, it will most likely not be until the 22nd century. This is not known for sure, but we do know that the population will continue its robust growth for the rest of this century. With this growth will come the increasing challenges of health and sustainable living.
Over three billion people today live without proper sanitation, and over one billion do not have access to clean, drinkable water. Nearly one billion people go hungry. About 1.3 billion people do not have access to electricity. The picture is very clear that we have some serious adjustments to make, with or without ZPG. Common sense says what we do today, and the responsibilities we adopt and accept today, will be amplified in our own lifetime and exponentially felt in our children’s future.
There is no room for perpetual growth. It is a foregone conclusion that we will not survive it. If it grows unabated, the human population will reach the point where all its life-sustaining systems will simply breakdown and begin to succumb to disease, malnourishment, starvation or toxic pollution, ensuring its own demise. Or will humans sustain themselves? Humans have the innate capacity to make things right, even in the most adverse conditions.
Nature will always find a way to recover, reclaim itself and live on. Can mankind do the same, or will today’s existing species of humans, Homo sapiens, go the way of its ancestors, only to be replaced by another species of intelligent life?
The Day of Seven Billion has come while the human population continues to click on at about 2.5 births per second… and the beat goes on.
Did You Know…?
- In 1900, only one out of ten people lived in cities, but by 1994, one out of every two people lived in cities. Today, three billion people live in cities. (Source: U.S. Census Bureau)
- Antarctica is the only continent that does not have an indigenous population. Only about 1,000 people live there at any given time as researchers and scientists from various countries who study Earth’s geology, weather and related science.
- Every minute, a woman dies in pregnancy or childbirth. An African woman’s lifetime risk of dying from pregnancy related causes is one in 16. For Asian women it is one in 65, and one in 1,400 for European women. (Source: U.N. Population Fund)
- The top 20 percent of the wealthiest people in the world today consumes 86 percent of all goods and services. The poorest 20 percent consumes only 1.3 percent of all goods and services. (Source: World Population Awareness)
- Five of the largest groups of Australians born overseas are from five countries: United Kingdom, China, Italy, New Zealand and Vietnam.
- According to the U.S. Census Bureau, the world’s human population will reach seven billion in early March 2012.
