Overused tropes: earth is overpopulated

Of all the unused tropes I think that of the world being too full of people comes up the most. I understand the reason for it, if there are starving people there must be a shortage of food right? Same for not having houses for everyone.

The problem is that that is not how economics works, nor does every country operate every farm at the same efficiency.

North America, Central America and the Caribbean, have about 6,050,697,738 acres of land. If we moved everyone to north America we would each have almost an acre, and about double that if you included South America.

We are not starved for land, and that does not count the truly desperate and expensive things like going underground or making islands.

*Before I start please note I am not a professional farmer or doctor or anything, nor do I care to get the math exactly right, I only want to get it close enough to prove my point*

If we used aeroponics (spraying roots with nutrient rich water rather then keeping them in soil) and planted sweet potatoes (very high calorie food), we could feed something like 49,000 people per square kilometer (link, link). We could feed more if you had artificial light and stacked the farms on top of each other.

Without any artificial light you could feed the earth on farming or about a fiftieth of south America. In reality you would want more for variety, but even so I think I have made my point. If we wanted to, we could live and farm in the America’s then use the rest of the world for industry and parks.

Of course we could go even more drastic and farm algae in the ocean, (the most efficient food source we know of). This would mean we would not need to use any land for farming at all.

That is the reality. The world will not starve nor will we run out of space anytime soon. That however does not mean that everyone is well fed and housed. You can of course have a class of people who starve for economic reasons even if the food to feed them exists, or at least the production capacity exists to do so.

Now if you still want to have a world food shortage as part of your plot, then I suggest you think about why food production would be cut by several orders of magnitude and stay cut.

Sunlight would be my go to in this situation. If something is stopping enough light from getting to the surface of the earth that would mean we would have to make up the difference artificially, and that takes a lot of power. If light was that low, we would also need power for many other things, such as heating up ect. Food would become very expensive and I could believe we would only produce enough to get by and no more. The same would apply to heat.

An obvious approach might be to lower the water supply but it does not work as well as you might think. The human body does not expend water, we just hold onto it for a bit then put it back into the environment. While not 100% efficient by far, its not like electricity that is made, used and then gone.

Also water is so important for so many things that we will always give it high priority. A lack of water could change the cost of certain foods but I can’t believe it would push us to starvation. If we ever reached that point we would have much worse problems to deal with.

Honestly, where there are any number of things that could cause a temporary dip in our food production, there are not that many that would decrease it long term. Even if large amounts of soil became non-viable there are ways around that. The only other one that comes to mind is if something stopped us from using machinery, like the sun starting to emit a continuous EMP.


Scarcity is the most basic concept in economics, its the idea that there is not enough supply for everyone to have everything they want. This of course, is what money is for, it’s used as a means to decide who can have what (put very simply).

One idea that you see now and then in science fictions is the idea of post-scarcity, of everyone having everything they want. A post-scarcity society would be one in which everyone has everything they want.

The problem with this is that I doubt there will ever be such a thing as post-scarcity, because humans always want more. When you free up resources you find other things to use them for.
We have passed through several instances of what could have been called post-scarcity.
There was a time when having enough food to eat every day and living to see your kids grow up was a pipe dream, something that rarely happened. Whereas now for many people those are a given and medical care is considered a basic necessity, something that only existed on a basic level not that long ago on the scale of the human race.

At some point we will pass through post-scarcity again, not in my lifetime to be sure but it will happen.
That said the question becomes what happens then? What do we then strive for?
And for that matter will we ever reach a point where most people can’t contribute to the betterment of our society, after all a great many jobs were no longer needed with the industrial revolution, what happens when most people are simply not able to do anything to help?

Scarcity, post or otherwise can be the source for many good stories, and is something that is often relegated to the background rather then the forefront.

What if the only people with jobs are those who would be top of the field today? If computers could do even the work of the average engineer or scientist and the only people working left are creative geniuses who do work only they can do.
Even artists may not be immune, if you could describe exactly what you wanted to a computer and it would make your a painting or a sculpture how many would be left?
What would you do in a world like that if you wanted to be one of these few but fell short, how would you give your life meaning?
And of course there is the problem of how you find these top people. Would everyone have to go to school just to find the top 0.01% of those who can push the field forward? Would you have extremely hard, competitive schools to find them? How many parents would not be ok with that? Would they push children too hard because of the prestige of being parent to one of them?
Maybe it would be brain scans and genetic mapping so you could be told from a young age you could be the next Newton. This could easily breed resentment, watching everyone else spend their time relaxing with no responsibilities while you are studying so you can spend the rest of your life working. potentially even to the point of putting you in some kind of stasis if there are too many in that generation.

One of the more depressing possible outcomes is that society stagnates. Everything is done for us so no one wants to do anything. If your options at 18 were to go to school for another ten years or retiring, how many people would keep at it? How long before whole specializations are empty?
This idea is far from new. Less thought about is what is done after. How about if your part of a society that has almost collapsed because of the above and you want to set your new course to one that won’t lead to your own destruction, what do you do?
If you have the technology to provide everyone a comfortable life where they will never want for anything but if you do you will doom yourselves what would you do? Would you artificially lower the quality of life low enough to create the desire to work?