Is overpopulation killing the planet?
Some experts predict global population may peak as early as 2050 or at the latest by 2100
Are there too many people on the planet? It's an incendiary question and rapidly gets political. But is it the reason why environmental crises keep growing in severity — especially climate change — and show few signs of being resolved?
In the fall of 2022, the global population surpassed eight billion people. Never before in human history has it been so high.
It took only 11 years to add a billion people to the planet since it reached seven billion in 2011. Estimates vary on when the world population will peak — as early as 2050 or by the end of the century at the latest.
Overall, about 80 million new people are added to the total every year — or "the population of Germany," said Robin Maynard, director of Population Matters, a UK-based charity that campaigns to achieve sustainable human population levels.
"I was born in 1958," he said, adding that, "[the world's population] has more than doubled over my lifetime."
Yet trying to get the public, political leaders, media or mainstream Western environmental organizations interested in discussing population growth is extremely difficult, said Maynard.
"It's a minefield and provokes strong reactions. But it also provokes, I would say, dishonesty and cowardice amongst otherwise intelligent people who… if you look at the science and if you look at the evidence, the facts are plain."
The politics of 'overpopulation'
Population growth is one of the biggest reasons why carbon emissions continue to rise — and climate treaties keep missing their targets.
Most experts agree the carbon reduction targets established at the 2015 Paris Agreement to keep temperatures from climbing above 1.5 degrees Celsius are not going to be met.
The United Nations advisory body, the Intergovernmental Panel on Climate Change (IPCC), has said that to meet that benchmark, emissions must fall by 45 per cent by 2030 compared to 2010 levels — a prospect which seems highly unlikely at this juncture.
And it's not hard to see why.
Consider the following: in 1988, NASA climate scientists testified before U.S. Congress, saying that climate change was actually happening — and was no longer a theory. At that time, the world's population stood at five billion and annual carbon emissions were about 22 billion metric tonnes.
By 2022, carbon emissions had risen to almost 38 billion tonnes — an increase of about 16 billion tonnes over 1988 levels. Adding three billion people to the planet since 1988 is one major reason — given that each human has a carbon footprint, averaging four tonnes per person per year.
Yet getting people to discuss population and its link to global warming is not easy, as I discovered when I embarked on my documentary for IDEAS. One of the experts I spoke with is Thomas Homer-Dixon, executive director of the Cascade Institute at Royal Roads University in Victoria, B.C. The reluctance to talk about the subject, or even to use the term "overpopulation," is shared on both ends of the political spectrum.
"There's been kind of an alliance between the right and the left not to talk about it because the left thinks that the issue is just a device for various forms of systemic racism to be perpetuated within societies and to sustain the current dominant economic structure," said Homer-Dixon.
"The right thinks that if you just let markets rip and human ingenuity stimulated by those markets flow, then human beings can respond to all of the challenges that population growth might be contributing to, whether it's concerns about food shortages or climate change or deforestation or land degradation and the like. So that alliance between the left and right has basically made it very difficult to raise the population issue in a way that isn't simply a caricature."
For example, The Guardian environmental columnist George Monbiot argued that population growth was not the cause of climate change — that instead it was overconsumption, especially by people living in richer, more developed countries. As he accurately noted, most population growth occurs in developing countries which produce far less carbon emissions than wealthy nations — yet historically have been blamed for having too many people.
Monbiot wrote that many of the people concerned about population did so under the guise of thinly veiled racism or embraced far-right politics.
Yet it's a far more complex topic than initially meets the eye. The reason: population growth is inextricably linked to the sources of energy that contemporary societies rely on.
The exploitation of fossil fuels
Prior to the 1800s, communities depended on energy produced by plants processing sunlight through photosynthesis. Plants were then consumed by humans or domesticated animals that fuelled their muscle power. Wood and limited use of wind power were the only other sources of energy.
These rudimentary forms of generating energy meant most people were forced to live on the land to eke out an existence. That fact also meant that population growth was incremental and lifespans often brief.
Between 800 – 1800, the world's population rose from 240 million to just under one billion — while in Europe average life expectancy was between 30 and 40 years.
The exploitation of fossil fuels like coal, oil and natural gas meant civilizations no longer had to rely on the limited energy produced by human or animal muscle power: By 1900, coal was the primary industrial fuel, which has three times the energy density of wood. Coal became the fuel for ships and locomotives.
The first commercial oil well in the U.S. went into production in 1859. Oil was soon powering automobiles and eventually airplanes. By 1964, it had overtaken coal to become the world's largest energy source. Fossil fuels also generate electricity (63 per cent in total).
Today, 80 per cent of the world's energy comes from fossil fuels and is the lifeblood of the global economy — not only for generating electricity and transportation, but for chemicals, clothes, plastics and potent fertilizers. Which bolstered food production.
Overall, fossil fuels and new agricultural technologies meant fewer people were needed to live on the land. They led to better and more consistent nutrition, public health infrastructures and access to medical care — all of which led to dramatically lengthened lifespans, and a population explosion.
By 1900, the global population had reached 1.6 billion. By 1950, it was 2.5 billion. And by 1968, 3.5 billion.
Brutal policies of population control
With that upward trajectory, concerns about the impact of population growth emerged. In the mid-1970s, India launched a mass sterilization campaign of men and women. People were randomly rounded up and taken to camps where sterilization procedures were carried out in crude conditions.
China, which then was nearing one billion people, imposed a one-child policy in 1979.
"It was a very coercive, very brutal policy," said Richard Smith, the New York-based author of China's Engine of Environmental Collapse. If families already had one child and the mother became pregnant, she was usually forced to abort the fetus.
We created a Pandora's Box because we didn't discuss population growth in the right way.- Vanessa Pérez-Cirera
Allegations of racism soon emerged – that those most concerned with population growth were rich people in the West blaming poor people in the global south for having too many children, when it's the inhabitants of wealthy countries consuming most of the world's natural resources and producing the most carbon emissions.
Overall, 50 per cent of carbon emissions come from 10 per cent of the wealthiest global population, while the poorest half are responsible for only 12 per cent of emissions. Africa has 17 per cent of the world's population and 1.4 billion people — yet produces only 3.8 per cent of the world's global emissions.
A person living in Africa will, on average, produce carbon emissions of one metric tonne yearly — compared to almost 16 tonnes for an average Canadian.
"I think we created a Pandora's Box because we didn't discuss population growth in the right way," said Vanessa Pérez-Cirera, director of the Global Economic Center of the World Resources Institute.
"And definitely I did see a tone of racism in those years and really the north pointing fingers at the south, which was growing faster."
The heavy-handed methods wielded in India and China to control population — along with associations of racism surrounding the issue — appalled many Western environmental organizations.
"In truth, there are almost no environmental groups who will talk about population [now]," said Maynard. "And it's because they're stuck in an ideological narrative which says you could only talk about consumption, you could only talk about capitalism."
But here's where the picture gets complicated.
For developing countries to achieve the same prosperity as wealthier, more industrialized nations — they typically require fossil fuels to power their path to prosperity.
China is a prime example.
In 1990, China produced almost 2.5 billion tonnes of carbon annually with a population of just over 1.1 billion people (or about 2 tonnes per capita), compared with the U.S. producing just over 5 billion tonnes with only 250 million people (or almost 21 tonnes per capita).
Starting in the late '70s, however, China decided to open itself to global markets and foreign capital — and become the workshop of the world. This unprecedented economic boom was fuelled by mostly coal-burning power plants.
As a result, with a population of over 1.4 billion people, China is today producing 11.5 billion tonnes of carbon emissions (or 8 tonnes per capita) — or almost one-third of the global total.
Renewables as a constraint
India, the world's most populous country, is following China's lead. While its annual carbon emissions are 2.7 billion tonnes, they've been rising steadily as the country's prosperity has increased, as have per capita carbon emissions (now almost 2 tonnes per person).
"They want the lifestyles and the opportunities that we take for granted in our societies," said Homer-Dixon. "And right now, the only real route for them to get there is to continue mobilizing, capturing and using a lot of fossil fuel energy… And that's really the fundamental dilemma that we're facing as a species."
This reliance on fossil fuels has now come with an alarming cost — namely the climate crisis. And so far, only 11 per cent of the world's energy comes from renewables, such as wind, solar, hydro and geothermal. Today, there are efforts to increase the use of renewables.
But Homer-Dixon argues that "we cannot run modern industrial civilization on wind and solar power by themselves." He points out it would take an enormous amount of land or space in the oceans to make way for solar panels and wind farms to replace fossil fuels.
"So this is a fundamental constraint."
Is there a solution?
Population growth also impacts biodiversity. As populations expand, they require more land to build homes and grow crops. Which means bulldozing forests and wetlands and other habitats, polluting rivers and lakes and air.
In the Amazon, farmers and ranchers have for decades been clearcutting the rainforest to graze cattle and plant crops to feed the world's growing population.
In 2019, scientists warned that one million species — out of an estimated eight million — are threatened with extinction.
Even as the world moves toward renewables, the gains made by cutting emissions could be undermined by continued population growth. The reason: every new person has a carbon footprint.
"If we had three billion people on the planet rather than eight going on to nine or ten, then we would have more room and more time for getting our carbon dioxide emissions down," said Homer-Dixon.
So what's the solution? As nations industrialize, they eventually see flattening and even declining rates of population. Yet that correlation hasn't prevented the global population from continuing to climb.
Most advocates argue the solution may lie in empowering women — providing them access to education, jobs that pay good wages, family planning and abortion services.
"As we learn more and have access to information, we understand that there are very effective measures to slow down population growth so we can all meet everyone's essential needs," said Pérez-Cirera.
"And women play a very key role in that. There's sweeping evidence across the world that educating women and giving them equal rights to services and other social services, etc., is one of the most effective ways."
Guests in this episode:
Robin Maynard is the director of Population Matters.
Thomas Homer Dixon is the executive director of the Cascade Institute at Royal Roads University in Victoria, B.C.
Vanessa Pérez-Cirera is the director for the Global Economic Center at the World Resources Institute.
Richard Smith is the author of China's Engine of Environmental Collapse.
*This episode was produced by Bruce Livesey, with help from Greg Kelly.
