Qualicum Institute: Advocating a science-based understanding of ecological, social and economic survivability

Population Growth

Infinite population growth for humans (or any species) is not ecologically sustainable

Pressures resulting from unrestrained population growth put demands on the natural world that can overwhelm any efforts to achieve a sustainable future. If we are to halt the destruction of our environment, we must accept limits to that growth.” Scientists First Warning to Humanity1

The Union of Concerned Scientists (UCS) who first published this document added a disclaimer to their document, acknowledging that the topic of over-population is considered problematic for various reasons. And the topic remains controversial, as many fear the darker aspects of humanity attempting to control populations. 

It’s not just the USC that wants to avoid discussion of population growth. Leon Kolankiewicz, an environmental scientist with several decades experience working for and with government agencies writes:

At both the national and international scales, the environmental establishment (Big Green) and climate activists alike have for decades either avoided or disparaged the population issue out of some combination of cowardice, calculation, apathy, ignorance, inconvenience, ideology, political expedience, or hypocrisy.”2

We have tackled some of the misconceptions that lead to this reticence about population growth in our Population Growth Quiz, and discuss them further below. 

Population growth: Feeding 8 billion and more

Many of the world’s most important food-producing areas are already compromised. Water sources for agriculture are drying up or have been contaminated. For example, in the American Midwest, the great Ogallala aquifer, which supports 25% of US agricultural production, is being depleted at a rate 3 to 50 times faster than it can be recharged. In some areas of the American High Plains hit by drought, the aquifer has already been drained.

Salinization – due to intensive irrigation, upstream dams, mining, and sea level rise – is poisoning freshwater and soil in agricultural areas around the world: e.g., the Mekong River delta of Vietnam, the Brahmaputra and Ganges deltas in India and Bangladesh, the Murray-Darling river area of Australia.

It can take 500 to 1000 years3 to make one inch of topsoil and the UN Food and Agriculture Organization warns that up to 90% of topsoil may be at risk by 2050.4

Topsoil, an indispensable resource for agriculture, is disappearing: at current rates of loss, the world’s usable topsoil could be gone in 60 years.

Population growth will only lead to greater destruction, and even elimination, of this non-renewable natural resource.

Population growth requires intensive farming which leads to soil erosion
Population growth leads to intesive agriculture which leads to soil erosion

And what will rising temperatures do to productivity? Rice, a crop that supports nearly half the world’s people, is particularly vulnerable to heat. A 1oC increase in night temperatures above 35oC can result in a 10% decline in yields.

So there is no good evidence on which to base the hope that there will be enough food for everyone. Even if we can manage to create a more equal world – one in which rich people give up meat, waste nothing, and readily share their wealth—there will not be enough to go around. Already 10% of the world’s people are hungry. As climate change advances, this percentage will grow. Adding more people to the planet will only increase the suffering.

Population growth to 8 billion: Good news or alarm bell?

When the world reached “Eight Billion Day” in November 2022, the UN Population Fund saw this as good news: “In November 2022, the world population eclipsed 8 billion people. For many of us, it represented a milestone that the human family should celebrate — a sign that people are living longer, healthier lives and enjoying more rights and greater choices than ever before.” The report dismissed fears about overpopulation as “alarmist.” (See the Population Fund’s report Eight Billion Lives, Infinite Possibilities.)

But is reaching 8 billion worth celebrating? What are the implications for climate change, energy use, food resources, and biodiversity?

Let’s look at just this last point. In the past 50 years, wildlife populations have declined by nearly 70%. The major cause of this decline is habitat loss, and the major cause of habitat loss is human activity – in other words, human competitive pressure. We use the land for housing, for highways, for mines, for forestry, for agriculture. With more people to house and feed, nations annex more land for human purposes.

The more land we appropriate for our purposes, the less there is for other creatures. Declining biodiversity is not just a sentimental question of losing whales or elephants or rare plants. It’s a matter of survival. We need the organisms – insects, flowers, trees, soil microbes, predators, grazers – that tie ecosystems together. Their activities create the fresh water, soil, and air on which we all depend.

And let’s have some perspective on the rate of increase. The overall rate of increase in human numbers is staggering: In 1970, there were fewer than 4 billion people. Fifty years later, there are twice as many. The last billion were added in just 11 years.

Perhaps, as one critic has suggested, the UN’s report should have been titled 8 Billion Lives and Counting, Infinite Consumption and Pollution.

Will population growth stop when all nations achieve higher standard of living?

Concerns about the size of the human population are often waved away with the confident prediction that once the less poor nations reach a certain level of development, their populations will stabilize. This sounds like a win-win solution: help the poor become rich, and population pressures will go away. But it won’t work. The planet does not have enough resources to bring 8 billion (or the 9.7 billion the UN predicts for 2050) up to a reasonable standard of living. (As a measure of “reasonable,” we are using the current footprint of Spain. It is half of Canada’s, but Spaniards on average have comfortable lives, with adequate food, shelter, education, etc.)

What would a sustainable world population of humans be? Sustainable means that humans are not extracting more from natural systems than can be replenished, and not producing more wastes than natural systems can absorb. Most estimates settle at around 3 billion humans.

Are drastic measures required to stop population growth?

Many people fear that slowing population growth will require inhumane policies such as forced sterilization or “one-child” laws. They assume that taking action on population growth will inevitably violate women’s reproductive rights. But this is simply not the case. Successful voluntary programs in Iran, Indonesia, Costa Rica, Thailand, and the Indian state of Kerala have demonstrated that family size can be reduced without coercion. Moreover, reducing family size leads to an increase in family income.

For more discussion, visit https://overpopulation-project.com/.

Solutions to Population Growth

For humane ways of addressing human overpopulation visit: https://mahb.stanford.edu/library-item/solutions-overpopulation-can/  

Stop ecological overshoot caused by economic growth

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