Is the Earth overpopulated? How do we decide?

**(Suggested) Rules of this thread: Please read!

I had half a mind to start this new thread on Great Debates because so many questions that appear neutral in character and content turn out to be minefields of liberal/conservative, right/left, Catholic/non-Catholic, socialist/capitalist controversy.

I am not unaware that this question is connected to a wide range of other debates regarding contraception, environmental issues, etc.

But while I am not a moderator, I wonder if I could ask the cooperation of both moderators and posters in maintaining a Socratic dialogue? Your cooperation would be apreciated.**

Let us start by agreeing that if we use the word “overpopulated” we must mean “populated above and beyond a certain desirable or perhaps crucial point”.

So by what standards or with what measuring tape do we judge a planet to be overpopulated by a given species (in this case homo sapiens)?

First, I believe we can agree that sheer lack of space cannot be the benchmark we will use. We cannot say “The planet is overpopulated when there is no longer be enough land for everyone to stand on.”

Here is an interesting statistic. If you gave every one of the six billion humans (IS it still six billion?) a square metre to stand on, you could fit them all easily on an Island the size of Jamaica and still have almost half the Island left over.

Don’t believe me? Do the math. A square km. is 1000 metresX1000 metres=1,000,000 square metres. So every square km. would hold one million people, right? And a thousand square km. would hold a billion, right? Well, Jamaica has 11,000 square km. , or enough room for 11 billion people!!!

Now of course, this is purely a mathematical game to show that we humans as individual animals do not take up as much room on Earth as we suppose. But it could not work in reality. The problems of just feeding and sewage disposal of six billion humans standing on Jamaica would make it impossible to put even a fraction of those numbers on that Island.

But there are standards other than sheer physical space.

Most public rooms contain notices that “Occupancy by more than ____ persons is unlawful.” I assume this is put up by the Fire Department, and is based on something like how many people can mak it out the door in a given time?

Lifeboats on ships have maximum occupancies. This may be based on the number of seats, but it may also be based on the amount of water and emergency rations stored on the lifeboat, etc.


What measure would we use to determine whether our good old planet Earth is overpopulated or not?
Suggestions anyone?

When we start dropping like flies.

Sounds like a GD. Perhaps this thread should be moved.

I agree that this question is fraught with ideologic and political problems and you may have difficulty seeing through the “fog of war”, so to speak. Let me suggest this: choose another species, other than humans, and ask the same question. Surely the criteria would be the same, and you would have much less political crap to deal with.

All we need to know, in principle, is how much resources (food, water, metals, etc.) the Earth can produce per year in perpetuity, and how much of these resources each person requires per year. Divide the first number by the second number, and that’s how many people the Earth can support.

The problem arises when you start asking questions about what exactly is meant by the above statements. What level of agriculture is sustainable “in perpetuity”? How do we account for long-term effects that might not be at all evident today? Should we assume that future technology will be able to solve these putative problems for us, should they arise? What if we’ve neglected some resource that, centuries later, turns out to be critically depleted? Do we need to take into account the extra resources required to redistribute these basic resources around the world? When we say “how much resources a person requires”, is this for bare Third-World-style subsistence or First-World-style largesse?

This is where things veer off into GD territory.

Too much baggage to be a General Question.

Moved to Great Debates.


Thanks Mike, that is just the kind of point I was interested in discussing. I am reminded of the saying “The Devil is in the details”.

A couple of posters have suggested we switch this thread to GD. You know, I originally did not care much WHERE it was posted, but now I find myself formally asking the moderator NOT to switch it to GD. Why, you ask?

Because I would like to know if we humans have lost the art of socratic dialogue, the pursuit of facts for their own sake, the acceptance of conclusions that the facts lead us to no matter how we feel about contentious issues attached to those conclusions.

For example, try asking a question like “At what point after conception is a foeutus a human being and how should we determine it?” and you will immediately get both sides of the abortion debate lining up like armies on a battlefield who know exactly what side they are fighting on.

Some people will tell you that it is human immediately after conception. Others that it is not human until it is born.

What is more ridiculous, to believe that a lump of a few dozen cells is a human being or that eight-month premies, millions of whom have gone on to be normal human beings, were not human ten seconds before their head poked out the vagina? Both viewpoints are patently ridiculous. But try to have a rational discussion as to when you can draw the line about the humanity of the foetus and all you will get is people yelling at each other.

Because 99% of people have no interest in the truth, only in advancing their agendas.

It is possible to have an intelligent and impassioned discussion about how many people should be permitted in a public room of one size or another. It is possible to gather facts about fire evacuation, crowd control, exit rates, etc.

Is it really impossible to have a non-controversial discussion about how we would arrive at a definition of what constitutes “overpopulation”? If so, I feel sorry for the human race.

The problem is that no other species has the capacity to develop technology that makes it possible to support higher populations. The number of humans the planet can support in a “state of nature” (i.e. hunter-gathering) is a small fraction of the current population (even if you only count the part of the current population that doesn’t have to worry about missing any meals).

The other issue is, are you going to consider ONLY the welfare of human beings and the plants and animals they eat when considering overpopulation? Is there a rationale to preserving other species? And if so, how much should we/can we limit human population on behalf of those human beings?

I’ll give you a hint on my POV – large portions of the Middle East didn’t used to be deserts.

should read “on behalf of those species.

This concept/theme was the inspiration for the title of John Brunner’s Hogo winning Stand on Zanzibar. It’s a right good read.

I doubt we’ve lost the art, but how does that apply here? This isn’t a matter of just facts. It’s also a matter of definitions, assumptions, and choices - such as the ones you thanked MikeS for mentioning.

That’s exactly the kind of judgmental statement that leads a discussion into contentiousness. And it’s hardly demonstrable that either viewpoint is ridiculous - they both can be represented as points on a timeline. Given that somewhere on that timeline represents the beginning of a human being, it becomes an argument over “where?”, and “why there?”. And one’s answer largely depends upon many non-factual components. What’s the definiton of human being? Is it in a moral sense, or a legal sense, or a biological sense? If you honestly think that the answer is something that lends itself purely to rational argument and analysis of facts, I’d say you’re showing a rather shortsighted view of human nature.

Well, it’s certainly not as simple a question as “If a fire breaks out, how many people can exit this room before being harmed?” There’s rather little room for personal perspectives in that question, and an answer can be found from working with a short list of objective considerations. The issue of overpopulation, on the other hand, is fraught will personal perspectives and presents a long list of objective and subjective considerations. It’s pretty much an apples and oranges comparison.

It probably is impossible to have a “non-controversial” discussion regarding overpopulation. The very fact that there are too many variables that affect choices of definition eliminates that possibility.

It is, however, possible to have a non-confrontational or a civil discussion in which the various parties, even when they disagree, are at least open to trying to understand how the definitions are formed. Rather than assuming that the differences are based on closed minded agendas, look at the differences as varied perspectives grounded in varied experiences and try to learn from the “opposition.” If all the serious parties treat each other with respect, ignoring the few shrill slogan-spouting agitators, we can carry on the discussion civilly, even when the thread is punctuated by occasional outbursts of hostility and stupidity.

The difference is that you can ask a few people to leave an overcrowded room, or refuse to let any more in, without curtailing anyone’s freedom or civil rights or even causing them any great inconvenience. But when you consider solutions to overpopulation – well, some solutions are draconian, like China’s “one child” policy. And there are even more extreme solutions conceivable – e.g., genocide, or selective extermination of “useless eaters” or the “genetically unfit.”

Here’s a recent GD threat on whether the U.S. is overpopulated – many relevant points raised.

If the continual existence of X humans on the planet is not biosphere-sustainable, i.e., if it requires the extinction or slide toward likely extinction of other parts of the biosphere (species, habitats, bio-regions), then I would say that the human race, by definition, is over-pop’ed.

So, we are apparently already at that point. I expect mass killings.

Oh, look, there’s Rwanda!

Personally, I’d be fine with near-unlimited immigration to bring Canada’s population up rapidly. I’d want a few caveats, like an absolute written-in-stone ban on religion-themed laws, all immigrants undergoing fingerprint, retinal and DNA identification and any immigrant who is shown to have betrayed an oath of loyalty to the nation be deported to international waters.

The most objective and evidence based way to answer this question is to consider the total ecological footprint* of humanity and compare this with the planets biocapacity. Currently our ecological footprint exceeds biocapacity - we are not sustainable.

So Valteron the answer to your question is YES. The planet is overpopulated with humans given the current rate of consumption of resources. In the long term this will sort itself out though through some reduction of consumption (through recycling and improved efficiencies of production), famine and collapse of ecosystems.

This PDF of the Ecological Footprint of Nations shows that USA has a footprint of 9.6 global hectares per capita. This is at the top end of the scale, with countries like Bangladesh having 0.5 gh/capita.

It depends on your point of view.
Personally I think every human should have access to:

  • clean water
  • nutritious food
  • housing
  • an education
  • medical treatment
  • safety from violence

Since millions of people don’t have that now, I consider the Earth over-populated.

Have you got a cite for this?
Are you one of the 99%?

“Footprints” are certainly useful tools, but they are not inherently objective, (otherwise, every calculation of footprints would arrive at an identical conclusion, which they do not). Beyond that, I would note two criticisms of the inference you have drawn.

First, since population is only one aspect of the footprint calculation, I believe it is incorrect to claim that if the world has exceeded its biocapacity, then we are, by default, overpopulated. With no change to population, (or even with an increase if it does not get out of control), increases in food production, improvements in food distribution, improvements in recovering or replacing renewable resources, and reductions in the production of waste would result in both a reduction in the human footprint and an increase in the world’s biocapacity. In fact, the very .pdf to which you linked shows examples of those phenomena, today. Several European nations have been reducing their footprints and the global per capita footprint has shrunk every year since 1980. (Since the overall human footprint is increasing through the same period, this would tend to support the argument that population, itself, is the main current culprit. However, changes in existing societies (more food in underdeveloped countries, substitution of renewable for non-renewable resources, and less waste in developed and developing countries) could, conceivably, reverse the overall footprint.)

Second, the fact that we have currently exceeded the (variously described) footprint does not indicate that we are currently overpopulated. As an analogy, consider a corporation and its debt. A beginning company may borrow heavily to get started and an established and profitable company may go into debt due to various forces. However, debt, even for multiple years, does not equal bankruptcy. As long as the company takes steps to get itself out of debt before such time as all the loans fall due, it may survive not only that period of debt, but actually turn itself around to the point of carrying no debt. In the same way, the world may currently exceed some ratio of footprint to biocapacity analogous to debt, but that does not mean that we are actually overpopulated and cannot recover. It is certainly true that if we make no effort to change direction, we will probably become overpopulated, but the world has not yet reached the point of resource bankruptcy.
There is no place on Earth where starvation is the result of an inability of the world to produce food. Every case of starvation, currently, is due to a lack of distribution, not production. The currently large footprint(s) are attributable to excess toxin production and reduction of renewable resources (debt). We may be too foolish to turn those trends around, but the fact that we are currently in a deficit does not equal bankruptcy.

Based on this definition, it appears that the world has never had a period in which it was not overpopulated, even when there were only a few thousands of persons scattered across the Earth.