Overshoot: Is Overpopulation Really the Issue?

This article is me thinking out loud.

I am not diagnosing anything. Rather, I'm simply wondering.

I'd love your feedback in this open discussion.

It's clear that humanity has overshot the planet's ability to sustain life. Mother Nature is under attack from all angles - ocean acidification, global heating, biodiversity loss, extinction. I'm sure you've seen this graphic before:

Intuitively, one would conclude that there are too many humans. If there were fewer humans, we'd consume less and resource exploitation would be more sustainable.

But is this correct?

I'm not disputing the fact the collective 'We' have overshot equilibrium. What I'm wondering is whether the outcome would be any different if we had half the population. There's no real way of knowing, so this is a thought experiment that I've love you to help me with.

Hear me out.

First of all, most of the accumulated planetary damage has been inflicted by a small proportion of the global population.

According to Oxfam:

• The richest 1% (77 million people) were responsible for 16% of global consumption emissions in 2019—more than all car and road transport emissions. The richest 10% accounted for half (50%) of emissions.
• It would take approximately 1,500 years for someone in the bottom 99% to produce as much carbon as the richest billionaires do in a year.
• Every year, the emissions of the richest 1% cancel out the carbon savings coming from nearly one million wind turbines.
• Since the 1990s, the richest 1% have used up twice as much of the carbon we have left to burn without increasing global temperatures above the
• The carbon emissions of richest 1% are set to be 22 times greater than the level compatible with the 1.5°C goal of the Paris Agreement in 2030.
• In the United States, Oxfam research reveals that a person in the top 1% emits 25 times as much carbon pollution as a person in the bottom 50%.
• Additionally, while people in the bottom 50% of income reduced their emissions by more than a fifth over the past 30 years, those in the top 1% have not reduced their average emissions at all.

NB: While you may not feel this way, if you live in the Western industrialized world you are part of that 10%.

So if only 10% of the world is responsible for 50% of all emissions, the link between global population and climate catastrophe becomes less direct. Billions of people in developing countries could vanish overnight and it arguably wouldn't make much of a difference to total emissions.

Perhaps eliminating the 10% would do the trick? Maybe temporarily, but that would leave a void for a portion of the 90% to fill. Soon enough, a new cohort would be leading the modern middle class+ lifestyle they've always desired.

Let's get away from proportions and look at absolutes. Yes, there is a top 10% responsible for most emissions, but what if that 10% included 300-400MM people instead of close to a billion. In other words, total global population was only about 4 billion. All things equal, one would assume emissions (etc.) would drop significantly.

Here's where I perform mental gymnastics to suggest that a significantly lower population wouldn't actually make a difference.

Imagine the global population stopped growing at 4 billion - the population in the early 1980s. From 1980-on, we had the growing resource and technological capacity (which are highly correlated) to add more babies but we didn't.

So where does that excess productive capacity go if not to support additional humans? It's unlikely it would be left untapped, due to competitive forces.

In simplistic terms, real (i.e. after adjusting for inflation) economic growth is the combination of population growth and productivity growth. If population was held constant (i.e. population growth was zero), the economic capacity that would have supported additional humans would instead be spent supporting existing humans, increasing productivity growth. Fewer people would produce and consume more.

Looking at this at the micro-level, consider a dual-income couple earning $200k. If they have a child, their resources would be spent feeding, clothing, educating them. If they remain childless, they would spend more on themselves - bigger vacations, fancy cars, etc.

Could we not expect something similar on a macro scale? In the end, we'd have a smaller but more resource intensive population.

If population collapsed chaotically today - perhaps due to multi-breadbasket failure - resource consumption would fall dramatically and possibly permanently. However, one could argue the survivors would eventually pick up where the deceased left off, leveraging technological capacity to produce and consume more.

As I write this, I'm starting to wonder if it's technological capacity rather than population is the real root cause of our situation. Historically, we applied that technological capacity to human survival, exploding the population. If we hadn't, the capacity still exists and would be used elsewhere (i.e. higher per capita consumption).

This line of thinking feels counterintuitive, but it certainly seems the idea overpopulation is the root of all our problems isn't definitive.

Would things be any different if we held population constant at 2, 3, 4 billion?

Would a population crash today help or simply delay the inevitable?

Please let me know what you think in the comments below: