The Magical Number of Humans Earth Can Support
By: Kristy Lynn
Tags: World, Science, Climate Change, Humanity, Environment

The Magical Number of Humans Earth Can Support

Why we need to talk about carrying capacity — now.

Photo by Cem Ersozlu on Unsplash

“The world has enough for everyone’s need, but not enough for everyone’s greed.” ― Mahatma Gandhi

Overpopulation. The topic that’s least likely to be discussed at your post-COVID dinner party. I know it doesn't entice Medium readers like sex, relationships, soulmates, and productivity topics do — but it should.

Because it’s literally a matter of life or death.

My heart is heavy even broaching the subject. And, yet, we must understand how science explores this pressing topic. *Quick note, I’m not a scientist, so those of you who are, please join this discussion and tell me what I am missing or where I may be misinformed.

My Middle School Science Class

Now, back to me, not being a scientist. Although that’s true, let’s not disregard the science classes I took throughout my school years. I’m embarrassed that I don’t remember much except the egg drop experiment — that confirmed why I shouldn’t jump off the roof of a building. Oh, and the volcano explosion experiment — that made me not want to ingest vinegar and baking soda at the same time.

But one concept has stuck with me for 20+ years. For some unknown reason, the idea of carrying capacity has stood out in my childhood memory bank.

I distinctly recall my middle school science teacher saying that the Earth had a limited number of resources able to support a limited number of animals. (By the way, that includes humans since we’re animals too. Except maybe some of those mega-billionaires, that’s still debatable).

I consulted Professor Google to check my memory and see if I’m correctly recalling this 20-year-old fact of mine. Wikipedia helped explain:

“The carrying capacity of an environment is the maximum population size of a biological species that can be sustained in that specific environment, given the food, habitat, water, and other resources available.”

The Magical Number of Humans Earth Can Support

You probably know where I’m going with this, hence my heavy heart. When I first heard about Earth’s carrying capacity, I learned that our planet could support only a specific number of humans. Anything over that number and we entered fatal territory for our species. I couldn’t remember the exact number, but my gut said it was somewhere around 7 to 8 billion — which is where our global human population currently resides.

A quick fact check on myself revealed some interesting news. There is plenty of healthy debate in the scientific community surrounding this magical number of humans the Earth can support. The Australian Academy of Science has a great summary of the number of studies conducted to determine Earth’s carrying capacity and each numeric prediction. Suffice to say, it’s all over the board, from 2 billion to 1,024 billion humans. The uncomfortable truth, however, is that most of the studies show the magical number is 8 billion.

8 billion humans is a consistent estimate from multiple scientific studies for Earth’s carrying capacity.

Please recognize the current global estimate for the human population is 7,856,055,811 at the time of this writing. This is an estimate based on an educated guess that 200,000 humans are born every day. That number is alarming, even as an estimate. Primarily because — it’s so close to 8 billion.

Scientists predict that humans could reach a population of 8 billion by 2023.

That’s only 3 years away.

I’m not doing this to doomsday people. I’m doing this to educate. To shake us out of our slumber and recognize that exponential growth of any kind (human life, economic, housing development, etc.) and Earth don’t mix. That’s not how planet Earth operates. Our planet is giving and abundant. Also tolerant and resilient. But — like all of us — even the Earth has limits to how much it can give. And, we need to respect those limits, or else.

But there is a small beacon of hope beyond education and awareness of the issue: the advent of technology — as long as we properly use it.

18th Century Carrying Capacity Meets 21st Century Technology

The Englishman Thomas Malthus is credited as being the first to speak about carrying capacity. He made a prediction in 1798 about the capacity for Earth’s resources to support an ever-expanding human population. His prediction: it couldn’t do that. Primarily because the number of humans would outpace the amount of food produced — thus causing massive famines, starvation, and ultimately death. He’s right, on one hand. The only thing he was missing with his 18th-century prediction?

Facebook, Amazon, and iPhones — oh, and farm tractors.

Of course! Malthus couldn’t have predicted humans' amazing ability to create technology. He was living in a time of horse-drawn carriages.

This brings us to some good news. Humans can use technology to produce more food in smaller and more creative spaces, to generate clean energy, and to help conserve water. We also have a brain capable of mindful awareness to help us consume fewer resources per person.

The bad news? We’re not doing it. At least not at the massive scale needed. Unfortunately, the way we’re currently exploiting resources and utilizing technology is preventing us from expanding Earth’s carrying capacity. For example:

“Ideally, we would’ve switched en masse to technologies like solar power and electric cars long ago. Instead, we’ve used technology to simply extract and use more fossil fuels. So instead of technology allowing us to live better on less, we’re living better on more.”

Also, instead of distributing resources more universally across the globe, developed countries tend to hoard them. The alarming statistic is that about 3/4 of the world’s population is barely living on what they need on a day-to-day basis, while the other 1/4 of the population (usually in more developed countries) is living rather extravagantly, by comparison.

If this is true, then carrying capacity isn’t merely a resource issue. It’s also a redistribution of resources issue. (Hence the reason I wonder if those billionaires are like us, or they’re something else?)

So What Do We Do?

By some measures, we’re already seeing the effects of reaching Earth’s carrying capacity: rampant disease, malnutrition, and destruction of the habitat, which is supposed to provide for us.

Besides educating yourself, believing in climate change, and making as many adjustments to your levels of consumption as possible, the most important thing you can do is vote! Vote with your dollar when possible — buy from companies who support ethical, sustainable practices.

And vote for government officials who value the planet and understand the gravity of our Earthly situation. Petition the government and corporations to do the right thing: use technology for the health of the planet, not against it.

And, you can have conversations with others about overpopulation.

Don’t Shy Away from Discussions on Overpopulation

Perhaps we shouldn’t be so afraid to broach the subject of overpopulation. We skirt around the issue because we think we have to talk about it in terms of death. But we don’t.

We must talk about overpopulation in a different way. Rather than talking about it as if the only resolution is that millions or billions of innocent humans must die to bring back Earthly balance, let’s talk about it for its real truth.

Because my takeaway from science is that overpopulation isn’t an issue that exists in a vacuum.

Photo by Antoine GIRET on Unsplash

Resource distribution and wasteful consumption are two huge contributing problems that compound the overpopulation issue. Too few people hold too many of the resources. And, those who own the resources aren’t wisely using them. Instead, it’s trendy for a small percentage of the human population to be massively, mindlessly wasteful of Earth’s precious gifts.

The problem is that some people own multiple homes, while others barely have a roof over their heads.

The problem is that some people throw out 30–40% of their food production while other people barely eat 1 meal per day.

The way I see it, we can talk about overpopulation and the Earth’s carrying capacity in two ways.

One: as if it’s inevitable that some people will have to be killed off the planet (but not us, of course) to bring about balance.

Or two: we can address it from the standpoint of overconsumption and redistribution of resources like the amazing, mindful, conscious humans I know that we can be. (Even you, billionaires!)

I choose the latter.

Which do you choose?