The answer, as with all big problems, is…. It’s complicated. Anyone who claims concern about human overpopulation is alarmist, leading to unwarranted panic, as Chelsea Follet does here, reporting in Forbes, doesn’t understand the scale of the problem.

This approach only seeks to understand the human perspective on overpopulation – i.e. how many humans can the Earth sustain?

Attempting to estimate the maximum numbers of humans that the planet can sustain, with no thought for the wellbeing, security of safety of the countless other species we share it with, throws a spotlight on the environmental problem of overpopulation.

After all we only need to glance at the numbers to truly appreciate that from the perspective of the natural world the Human population has exploded. A bright flash of intense heat spreading across the world and obliterating ecosystems and wildlife, leaving in its wake a bland patchwork of farms and fields interpreted with urban patches of concrete.

It is an uncomfortable truth to admit, but we are literally observers to this human explosion unfolding in real-time. We can see extinctions happening in less than the space of a human lifetime. And if advanced Alien lifeforms were watching our civilisations unfold and develop they would perhaps be wondering what kind of strange destructive force we are; our decimation of the natural world providing all the hallmarks of any other explosion.

So yes, we are absolutely in the midst of a human overpopulation explosion and yes, in the grand scheme of things it will be temporary. But the ‘grand scheme of things’ is a loose interpretation of time and, if we want to live in a richer world full of life, we have a responsibility to offer all types of creatures a quality of life.

Nor does it mean we should not be exploring the options for reducing our ecological footprint in order to allow other natural ecosystems and species the space to survive and thrive.

What Does Overpopulation Look like? What Are The Numbers?

It can be difficult to conceptualise just how many we are, but some comparisons against well known wild animals species may help.

• Humans are, hands down, the largest large-mammal species on the planet, coming in at a whopping 7.5 billion in number. That’s a difficult number to get your head around. In the 1960’s there were just over 3 billion of us and in the 1800s 5 million. That’s a a lot of human in a very short space of time.
• The next large mammal species are cows at 1.4 billion yoked into the service of us exploitative humans. We systematically impregnate female cows, take their calves to eat, milk them relentlessly and then kill them off after a few years.
• Sheeps, pigs and goats come in at a joint third at 1 billion each
• Dogs and cats; our domesticated pets that live with us, number a combined billion.

There are of course lots of other animals, rats for example number in the billions, and birds of varying species are also very numerous, depending on which ecological niche they have occupied. But if we are to consider wild animals species that don’t depend on human farming or cities for survival then the picture is a very bleak one. Purely wild species of large animals, those that live in their own ecosystems, are under huge pressure. We can compare the numbers against our own:

• 172,000 – 300,00 Chimpanzees left (our closing living natural relative)
• 200-300 Gorillas
• 6,600 Sumatran Orangutans
• 450,000 wild elephants in Africa with 100 being killed every day
• 35,000 to 40,000 Asian Elephants
• 3,890 Tigers
• 100,000 Giraffes in the wild
• 5,000 to 12,000 Blue Whales (the largest organism ever to have lived on Earth)

It’s a horrifying picture. And anyone who argues that the Human Explosion isn’t a problem for the natural world we live in, just doesn’t understand the scale of the problem. The focus remains on the extreme solutions; and those against limiting the human population argue that we have always used our greater intelligence to come up with the solutions.

In our human world, one which prioritises the human experience over that of all other animals, some can find it very difficult to understand that the human experience is the root course of so much suffering and environmental destruction. Suggesting that it is our population and our number that is the problem, can for some be extremely offensive.

But they need to get over it.

For a visual representation of this population explosion, which will leave little doubt about our human footprint, this indisputable graphic timeline from Population Education illustrates our explosion across the planet.

Wikipedia has a handy definition of overpopulation describing this scenario at play where an “existing if a population cannot be maintained given the rapid depletion of non-renewable resources or given the degradation of the capacity of the environment to give support to the population. Changes in lifestyle could reverse overpopulated status without a large population reduction.^”

And if we look at history we can begin to understand nature’s own checks and balances to correct times of overpopulation. Plague and famine kept humans in check from a natural perspective and tragic as they were, they limited our impact on the environment.

Human overpopulation comes about when the ecological footprint of humanity far exceeds the geographical location and its carrying capacity of the environment occupied by humans. People who argue that overpopulation isn’t an issue would say that the planet  can sustain far more humans than we currently have. Technically that’s true and technological solutions will, over time, increase the amount of food we can produce. But this argument fundamentally fails to take into account quality of air, soil and life itself. It also ignores the enslavement of most of the planet and the other species we have decided to farm in order to serve the needs of ourselves.

The legendary David Attenborough, a patron for the charity Population Matters has even weighed in on the debate concisely warning:

“We are a plague on the Earth. It’s coming home to roost over the next 50 years or so. It’s not just climate change; it’s sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now”

David Attenborough

What Are The Causes of Overpopulation?

Birth rates vs death rates

A high birth rate in developing countries combined with a decreasing death rate is at the heart of overpopulation. With the number of children born each year exceeding the number of individuals dying (and the age of human mortality increasing) the human populaton is exploding across the developing world.

Reduced child mortality

For most of human history the sad fact was that most children died at a young each from disease or malnutrition. With a massive reduction in child mortality more young people are surviving into adulthood.

Advancements in Medicine

Medical and scientific advancements have led to the survival of billions of humans. Before the development of medicines and vaccines, diseases such as small-pox, malaria and influenza ravaged humanity killing countless numbers of humans. Malaria, still a problem in parts of Africa and Asia is slowly being eradicated. Developments including vaccines, anesthesia and antiviral drugs are enabling many people, who would have previously died, to live long healthy lives.  

High Production of Food  

The Agricultural Revolution allowed humans to domesticate plants and animals, ultimately leading to large scale industrial farming practices that we see today, and enabling farmers to grow more food than they needed to feed their own families. This led to the development of human societies, art and culture, and the rapid expansion of the human population. And simply scientific advancements such as nitrogen based fertiliser have massively increased our ability to grow crops and feed and ever growing human population. Indeed Nitrogen-based fertilizer, developed in 1913, enabled us to grow yet more food. Without fertilizer, population analyst Vaclav Smil estimates, two billion fewer people would be in existence today.

How Does Human Overpopulation Affect the Natural and Human Environment?

• Reduces the availability of fresh-water
• Creation of dead zones in the oceons as a result of framing run-off and human pollution
• Increase levels of all types of pollution: water pollution, soil degradation, air, light and noise pollution
• Global warming as a result of increased CO2 emissions
• Destruction of natural ecosystems to create farming land to feed more humans
• Mass extinctions and loss of biodiversity as a result of new farm and crop lands being created
• Increased likelihood of new pandemics emerging as a result of intensive, closely confined, unhygienic farming practices
• Starvation, low life expectancy and malnutrition in developing countries with rapidkly increasing populations
• Conflict and warfare and poverty over rapidly depleted natural resources

This list goes on.

What Are the Solutions to Human Overpopulation

The solutions to tackling the human overpopulation explosion are remarkably simply and not quite as dramatic as the solutions proposed in Hollywood films like Wall-E (2008) – leaving Earth, Children of Men (2006) – Inferility, or Thanos’ radical population control solution in Avengers, Infinity War (2018) – genocide.

The solutions that will work require a carefully thought-out and compassionate approach to enriching and educating the lives of millions of people across the globe. Most analysts forecast a rise in the human population to the level of 10 billion people across the globe by 2050 but there are government policies that can be enacted that will encourage a population drop-off that will allow the human population to decrease to a more sustainable level in the future.

Examples from developing countries experiencing massive growths in populations show us that there are a number of tools available to help human populations stabilise and the WorldWatch Institute has identified nine key strategies (which Worldwatch Institute President Robert Engelman argues in the book State of the World 2012: Moving Toward Sustainable Prosperity) that, if fully implemented across the globe, could immediately start to reduce devasting impact of the human explosion on the natural world.

1. Provide universal access to safe and effective contraceptive options for both sexes. With nearly two in five pregnancies reported as mistimed or never wanted, lack of access to good family planning services is among the biggest gaps in assuring that each baby will be wanted and welcomed in advance by its parents.
2. Guarantee education through secondary school for all, especially girls. In every culture surveyed to date, women who have completed at least some secondary school have fewer children on average, and have children later in life, than do women who have less education.
3. Eradicate gender bias from law, economic opportunity, health, and culture. Women who can own, inherit, and manage property; divorce; obtain credit; and participate in civic and political affairs on equal terms with men are more likely to postpone childbearing and to have fewer children compared to women who are deprived of these rights.
4. Offer age-appropriate sexuality education for all students. Data from the United States indicate that exposure to comprehensive programs that detail puberty, intercourse, options of abstinence and birth control, and respecting the sexual rights and decisions of individuals, can help prevent unwanted pregnancies and hence reduce birth rates.
5. End all policies that reward parents financially based on the number of children they have. Governments can preserve and even increase tax and other financial benefits aimed at helping parents by linking these not to the number of children they have, but to parenthood status itself.
6. Integrate lessons on population, environment, and development into school curricula at multiple levels. Refraining from advocacy or propaganda, schools should educate students to make well-informed choices about the impacts of their behavior, including childbearing, on the environment.
7. Put prices on environmental costs and impacts. In quantifying the cost of an additional family member by calculating taxes and increased food costs, couples may decide that the cost of having an additional child is too high, compared to the benefits of a smaller family that might receive government rebates and have a lower cost of living. Such decisions, freely made by women and couples, can decrease birth rates without any involvement by non-parents in reproduction.
8. Adjust to an aging population instead of boosting childbearing through government incentives and programs. Population aging must be met with the needed societal adjustments, such as increased labor participation, rather than by offering incentives to women to have more children.
9. Convince leaders to commit to stabilizing population growth through the exercise of human rights and human development. By educating themselves on rights-based population policies, policymakers can ethically and effectively address population-related challenges by empowering women to make their reproductive choices.  

Whether of not we adopt a coordinated approach to the implementation of these strategies remains to be seen. Humans are undoubtedly the most successful species that has ever lived on planet Earth but then again… that really depends on how you define success. If success truly means living in harmony with your environment ensuring you respect natural laws and live within your ecological means, in order to ensure your own survival, then by that metric we could also say that we are the least successful species that has ever lived.

Whichever path we decide to take; we can be sure that the one that we are on at the moment is unsustainable. Huge challenges lie ahead and there will be massive strife and upheaval as humanity slowly wakes up, recognises its unsustainable impact on the natural world and begins to transition to state of being that respect other living things that we share this planet with.

Video credit: Population Education.