How many people should there be?

Dancer, Benjamin | November 22, 2016 | Leave a Comment Download as PDF

There is an important question I’ve recently started asking.

It’s a question of such importance I wish I could figure out how to get everyone on Earth to ask it, too. I think the future depends on it.

I know the question sounds strange. But what’s even stranger, at least to me, is that it’s something we don’t talk about. It’s taboo, even.

If we don’t ask the question “how many people should there be?” I doubt we’ll be able to decide the answer, and losing the initiative on that would likely be a catastrophe.

I think of it this way: our biology wires our population for growth. In other words, if we don’t make a collective choice as a species, the status quo will likely always be growth. That is up until the moment that further growth becomes ecologically impossible. In biology such an event is called a “collapse”.

Here’s a short version of the math.

There are 7.5 billion people today, and the growth rate of the population is about 1.1% per year, which means about 75 million people are added to Earth every year. 1.1% seems like a small number until you do the math. At that growth rate, the population would double in less than one lifetime, which would put us at a total population of about 15 billion in about 63 years.

Another way to illustrate the power of exponential growth is to look backwards. When I was born, 1972, the population was about half what it is now. When my grandfather was born, it was half of that.

After examining the math, it might be helpful to look at the issue philosophically.

There are some really important questions in life that I don’t think we should leave to the unconscious.

Take, for example, the question what type of parent do you want to be? I believe that question represents a life direction. If such a question is not approached with intentionality, the status quo of whatever mentoring we’ve received in our lives will become actualized within our own selves, with or without our conscious consent. In other words, we can either choose who it is we want to be, or we can unconsciously become like those who have, for better or worse, influenced us most greatly.

That might sound like a tangent, but I think it’s related. I think we ought to aspire to be more intentional because our lives are more meaningful when we’re more aware of our choices.

The size of the population is a collective choice. Now that we’re aware of that choice, I’ll rephrase the question.

There are about 7.5 billion humans alive today. We all need to eat. We all need clothes. We all need shelter. Most of us will secure means of transportation, comfort, entertainment. All these things require energy to produce. And all these things are being provided by the finite resources of our planet.

What do you think is a sustainable number for our population?

I don’t know a precise answer to that question. I suppose nobody does, as there are so many variables concerning lifestyle and consumption. But here’s what I know for sure: more growth is folly. We wouldn’t have to be as careful about sustainability if there were less people because in general, less people consume less.

Let me put it this way, when there were a few million humans running around the planet, they could do what they wanted, consume what they wanted. Even if they tried, they couldn’t hurt much. For example, a few million humans could have tried to chop down a massive percentage of Earth’s forests, they could have tried to deplete the ocean’s fisheries, and they could have tried to intentionally drive thousands of other species to extinction, and it would have required extraordinary planning, collaboration and ingenuity for them to leave such a large ecological footprint.

With 7.5 billion people it requires extraordinary planning, collaboration and ingenuity not to cause so much ecological devastation. For example, I recently learned from a NOAA scientist that global population growth has trended perfectly with rising atmospheric concentrations of C02 over the past 100 years. In other words, there is a correlation between our growing population and climate change.

I like the number two billion.

Not for any good reason. Mostly because that was the carrying capacity of the planet before the advent of widely available, reliable electricity, which brought several technologies online to expand the carrying capacity of the planet. Those technologies include fertilizer, pesticides, mechanical irrigation, infrastructure for clean drinking water, infrastructure for sanitation, advanced medical care, etc. Prior to electricity there were two billion of us. Now there are 7.5 billion.

So if I had to give my best guess at answering the question: “how many people should there be?” I’d say about two billion because I think that might be a sustainable number. Meaning, we’d all have a pretty good lifestyle that could be sustained for a long time into the future.

Joel E. Cohen offers a pretty engaging discussion on these lines in his book How Many People Can the Earth Support?

I feel pretty confident in saying that we’d all be better off if there were fewer of us. But how do we get there humanely? Especially since our livelihoods depend on growth. Just about every one of us makes our living off growth. I’m a teacher. Without population growth, I’d likely find myself out of a job.

So how in the world do you contract without creating a catastrophe?

Since the global population replacement birth rate is about 2.1 children per woman, choosing smaller families is an effective way to reduce the population over time. A collective choice to have families with one or two children would reverse the mathematical trend from a growing population to a population that is contracting.

Unfortunately, at the end of 2016 there are still large populations throughout the globe without access to contraception. Moreover, a lot of smart people I’ve interviewed believe that universal access to contraception will result in smaller family sizes globally. In other words, when given access to contraception most people choose smaller families.

I think it’s important, at this point, to offer a brief commentary on liberty. I’d like to see us chose a smaller population humanely. Some people think that’s not possible. For example, the “bad guy” in my thriller Patriarch Run, wants to reduce the population by killing you and me and everyone we love. He figured out a realistic way to do this (by taking down the power grid). I know a lot of people like him, not in their willingness to commit genocide on a scale never before seen in human history, but they share his pessimism about the future of population growth. I’m much more hopeful than that.

So let me posit this. A humane approach to this problem would also respect liberty. As a matter of fact, it could enhance liberty. I think we can agree that not every human being today is afforded the right to their own body and reproductive choices. For example, 2.5 million girls 15 years old and younger are arranged into marriage every year. I’d like to see the right of liberty universally respected, especially among young girls and women. One of the many benefits of the universal respect of human rights would be smaller family sizes, as most women, if given the choice, would likely choose to have one or two kids.

But what then? How do you manage the economics of population contraction? 

I don’t know. But I know this. If we don’t contract intentionally, mother nature will “contract” us. That’s just how biology works. Which is why I think it’s better to ask these questions than to run the whole thing off the cliff.

Benjamin Dancer is the author of the literary thriller Patriarch Run, the first book in a series that will include Fidelity and The Story of the Boy. He also writes about parenting, education, sustainability and national security. You can introduce yourself to Benjamin at

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