Ever since the Black Death in the 14th century, caused by the Bubonic plague, the growth in human population has been on a constant rise. And within the last century, these numbers have risen exponentially. Indeed, in 1927 the population on earth was estimated to be 2 billion. Less than 90 years later in 2016, we have a population of 7.4 billion and it’s continuing to grow.

There are several contributing factors that have led to this population explosion. The most significant being attributed to declining death rates. Thanks to modern medicine and technology, we’ve been able to overcome problems of widespread hunger and poverty. Fertility treatments and better medical facilities have led otherwise fatal diseases and defects to be recoverable. And today, we reap the benefits and comfort that these advances have provided us.

The question remains: Should we be concerned about overpopulation? Within the scientific community there is diverse opinion on both when and what amount the population will peak at before stabilization or decline. Scientific studies have ranges of time as early as 2050 to 2300 and beyond. Estimates for the peak of population hover between the 9-12 billion range. (1, 2)

However, many of these scientific studies don’t take into consideration the potential scientific breakthroughs that may occur over the next two centuries. What if, for instance, it becomes normal to live to be 150 or even 200 years old? Considering the existence of super-centenarians, we should remain open and optimistic to the idea of increased human longevity. This would push the figures well beyond what many of these studies conclude.

Likewise, it is also possible that science could revolutionize the resources we need to survive and flourish. We have a limitless supply of energy in the sun and it’s only a matter of time before we begin to harvest this energy efficiently. In addition, the continuous evolution of technology like 3d printers may have enormous effects in the way we manage our resources. These kinds of innovations could nearly negate overpopulation as a problem altogether.

Of course we should remain skeptical of such ideas. Regardless, it’ll be interesting to see how our population growth plays out over the next several decades and whether this growth becomes a major problem. If it does become a problem, what are the philosophical consequences? Will we need to enable policies that discourage people from having children? Would that be ethical?

The consequences of overpopulation are definitely reminiscent of those in dystopian fiction in many ways. And while this may be new territory for humans, overpopulation is nothing new for many animal species. When it does occurs to a species, it isn’t pretty. Nature has it’s own way of restoring order. One of two things tends to happen under these circumstances:

1. There becomes an increase in their predators which naturally reduces the species.
2. There becomes massive conflict over the remaining resources and there’s a major population crash.

Number one is common among several animals including snowshoe hares, deer and lemmings. If predators are not increased to keep the population low, number two becomes the inevitable result. Starvation and thirst becomes common, and eventually violent competition between their own species arises. However, some animals have learned to refrain from mating under such conditions thanks to their evolutionary pheromones. (1) Thus preventing conflict.

So how does this apply to us? Humans are apex predators, meaning we reside at the top of the food chain in which no other creatures prey. Therefore we would skip number one and go straight to number two. If humans weren’t to refrain from reproduction, we may escalate far beyond the violent skirmishes present in many animal species.

It’s important to note that many of these violent outcomes are only possible if we let overpopulation get out of hand in the first place. Nevertheless, overpopulation may still present problems including mass unemployment and a reduced quality of life for most people.

Whether or not overpopulation comes to fruition is yet to be seen, but the conversation needs to begin sooner rather than later. Someday, we may have to rethink our moral intuitions. For better or for worse.