We cannot confront our environmental crises without confronting our problem of scale. It’s time for a reality check, according to the director of Greenwashed.
by Sofia Pineda Ochoa, MD
Today, human overpopulation is treated as an outdated issue by much of the environmental movement. Raise the subject, and you’re likely to be met with sneering, jeering, and name-calling rather than serious discussion. “The population obsessives!” “Those dumb Malthusians”—chuckle, chuckle—“they actually think it’s about human numbers!”
Concern about overpopulation is often portrayed as somewhere between ignorant and morally suspect—a relic of outdated thinking from people naïve enough to believe numbers still matter to environmental degradation.
The environmental establishment has apparently moved on—to technological solutions, social justice, and a host of other concerns, while population itself has somehow come to seem unfashionable. The cool kids have declared the issue settled: overpopulation, they seem to think, is a non-issue and one that’s also very “passé.” So 1970s or 1980s. Not something enlightened people concern themselves with in 2026.

Rather like worrying about nuclear power. That’s passé too. So Cold War. In fact, nuclear is cool now.
Never mind that we still don’t have a long-term solution for radioactive waste, or that some of the radioactive waste we produce today will remain someone else’s problem for… well… only about 100,000 years. Never mind that Three Mile Island came frighteningly close to having a catastrophic meltdown. Or that Fukushima was both a disaster and, in many ways, a miracle. Had events unfolded only slightly differently, it could have been much worse; the Japanese government’s worst-case scenario envisioned the evacuation of around 50 million people (including Tokyo!).
No Explosion? Look At The Numbers
Speaking of explosions, a few years ago The Guardian published an article titled, “World ‘population bomb’ may never go off as feared, study finds.” The headline framed concern about overpopulation as somewhat alarmist rather than a legitimate environmental issue. Because if no population bomb is going off, then all must be good on that front.1
One hates to bring some bad news—a taste of reality—but guess what?
It already did.
The population bomb already went off.
It’s not some future event waiting to happen. It was the jump from two billion people to eight billion—a quadrupling of the human population in less than a century. Less than some people’s lifetime.
In fact, if you want to zoom out, an even bigger population bomb went off with the advent of agriculture some 11,000 years ago, taking us from a world population measured in mere millions to 8.3 billion today.
But if we want to stay focused on relatively recent events, we can safely say the population bomb went off with the Industrial Revolution. That’s when our dramatically increased access to food and energy helped propel humanity from one billion people in the early 1800s to more than eight billion today.
If multiplying our population eightfold in just two centuries is not a population bomb, then I don’t know what is.
And despite widespread confusion about population decline (people thinking that human numbers are shrinking when it’s only the rate of growth that’s declining) our global population is actually still growing by well over one million people, net, every week. That’s more than one million additional new lifelong consumers who will need housing, energy, food, clothing, transportation, education, infrastructure, roads, hospitals, and schools – every single week.
For example, in my film Greenwashed, we show how, with current net population growth, we’d need to build, finish, and staff the equivalent of more than 63,000 new classrooms every week just to keep up with our current growth, assuming we want every child to have access to education (1.26 million net population growth per week, assuming 20 students per classroom).Week after week after week. Building and staffing 63,000 classrooms—with cement, wood, books, finishings, everything—over and over and over.
It’s hard to imagine how this is not relevant to our environmental impacts—or, indeed, to providing people with a decent quality of life.
And with such dramatic growth, people may think, is that the problem? The growth we’re having?
The Pesky Little Problem Of Scale
Unfortunately, the population problem is not just about growth or growth rates. Not exclusively, anyway. Because even if our population had zero growth, or even if the global population were actually shrinking (which it’s not, but even if it were), our population would still be a problem for a long time. Because even without any further growth, what we have now is a serious problem of scale.
In Greenwashed, we talk about how an estimated 15 billion trees are cut down globally every year, which equates to roughly 28,000 trees every minute.
Every minute.
Even just for toilet paper, we use the pulp equivalent of more than 40,000 trees every day just to wipe ourselves. How can that ever be sustainable?
Well, you may say, if all that toilet paper is not sustainable, then we need to use bidets.
So, produce eight billion bidets?
Again, the problem of scale comes back to bite us in everything we do. Everything we touch. Every solution we come up with. Every aspect of our lives becomes a challenge when you have to scale it up to support eight billion people.
From energy to vegetable oils, our current scale is unsustainable and profoundly destructive.
Even the energy transition begins to look more and more like a pipe dream when we confront the material requirements of implementing it at our current—and still growing—scale. So, if we care about climate change, like we claim we do, shouldn’t we, for example, be realistic about the enormous quantities of minerals this transition requires? Their mining is already damaging ecosystems and is expected to expand dramatically in the coming decades. Shouldn’t we acknowledge the role population growth plays in climate change? The IPCC identifies population growth as one of the strongest drivers of increased CO₂ emissions, so why so much silence from the climate crowd that is otherwise anything but silent?
I don’t think the koalas burning to death as climate change intensifies would appreciate our silence on the matter—or the environmental movement’s selective choice to ignore and dismiss the population issue. For us and for the animals we share this planet with, overpopulation needs to be acknowledged and urgently addressed.
Denial Never Solved Anything
As a physician who specializes in psychiatry, I’ll tell you that, with my patients—whether they’re struggling with cocaine, alcohol, methamphetamine, or any other addiction disorder—understanding and acknowledging the problem is usually the first and most important step toward improving the situation. If you’re in denial, no progress can begin until you acknowledge the reality of what you’re dealing with.
And I think it’s no different here. Unless we understand and acknowledge that our scale is unsustainable and harmful—until and unless we truly internalize this issue—we cannot hope to address it.
Wild animals will continue to be in freefall because their habitat is being taken away by us humans. By our farms. Our roads. Our developments. We will continue to take their water for our own needs, depleting the water sources they depend on and making their survival harder. We will continue to take the land they depend on to grow our food and use it for our own needs. We leave less and less for them, gradually squeezing them out of the habitats they depend on for survival—and ultimately out of existence.
So, in addition to addressing consumption—which we absolutely must do—inequality, animal agriculture, the need to transition to plant based diets, and all the rest, we also need to put population back into the conversation. These things are not mutually exclusive. We can address them all in parallel, and we must, to have any hope of meaningfully confronting our environmental challenges.
How? By raising awareness of the issue. By being willing to acknowledge that overpopulation exists and that our scale matters. By normalizing that conversation and making that reality widely understood. I believe people would make different family-planning choices if they understood that we are overpopulated and that those choices have consequences far beyond their own families.
That is one of the central messages of Greenwashed, and I hope you get a chance to watch it.
Because with 8.3 billion of us—and still growing—trying to survive, trying to stay alive, and trying not to destroy the very planet and ecosystems we depend on to keep us alive, human overpopulation remains as timely and pressing an issue as ever.
Unless, that is, you consider our survival—and that of other species—something outdated and passé.
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1 Interestingly, the Guardian article itself told a rather different story than its headline. Published in 2023, it noted that the UN still projected the global population to reach 9.7 billion by mid-century and to continue rising thereafter. From roughly 8 billion at the time the article was released, that’s another 1.7 billion people—an increase of more than 20%. In a world already in serious ecological overshoot, that sounds rather bomb-like to me. As is often the case, when one looks beneath the reassuring headline, the numbers tell a less reassuring story. The most recent (2024) UN population projections have a most likely scenario of global population peaking at 10.3 billion in the mid 2080s, then tapering off to 10.2 billion by 2100.
