• Diane

The Great Filter

In a universe so vast, with countless galaxies, solar systems, stars and planets, it is unthinkable that we could possibly be alone. What is confusing to scientists is how we have not managed to have any contact or seen any signs of other intelligent species. It is so improbable that this is the case, it led scientists to name it the Fermi Paradox. Sure, we can not explore the entire galaxy, but there must be other life on other planets far more advanced than us. Right?

Maybe not. This could all be explained by The Great Filter.

When I first heard this term, not very long ago, my mind was blown. It’s the idea that we do not see species colonising space because this filter prevents any lifeform from becoming advanced enough to do so. That any intelligent species will destroy themselves before they can work out something as complex as leaving their own galaxy.

It feels to me like we are getting dangerously close to our filter. It could be that we destroy our planet to the point that we make it uninhabitable through the process of changing our climate. It could be that overpopulation, ease of international travel, and living on top of each other in big cities allow for the right virus to spread in a way that wipes us out. Perhaps a nuclear war due to political upheaval. AI could become advanced enough to overpower us. Or maybe messing around with black holes in labs finally catches up with us. There are so many existential threats to us at the moment, it’s frightening to think about.

But what could make it so that this filter exists for any species on any planet that becomes technologically advanced?

As humans, we started taking over as soon as we learned agriculture. No longer were we limited to what resources were naturally available. At that point, we broke the laws of nature.

Maybe we broke something else.

Does something happen to a species once they learn to control nature? Every species has a natural carrying capacity, a limit to their population numbers based on resources available. Obviously, we have increased our natural carrying capacity many times over. Carrying capacities are there for a reason, as it keeps nature in balance. We already see the impacts, the extinction rates of other species are off the charts and that’s just one example. It seems this could be true for any ecosystem.

So if the great filter does exist does that mean for us? I only see two scenarios at this stage.

Scenario One:

We continue as are we are with all the luxuries we are used to. Our population grows more and the average western person continues to consume more than is sustainable. The industries that are destroying the planet remain able to do so. We do this until we reach our filter, destroying ourselves in the process or pushing ourselves back to the stone age.

In other words, we have a good ride for as long as we can, without regard for allowing the human race to continue on.

Scenario Two:

A dramatic change in our way of life. We go back to community-based living. No more international flights. No more bananas from South America or cheap tech from China. We consume drastically less, taking only what we need.

This is a tough one. The amount of international cooperation needed is mind-boggling. I don’t see how it could ever happen unless we are forced into it. A complete economic crash may do the trick.


But what about green alternatives? Solar energy and the like? At this stage, that might be too little too late. Imagine the consumption needed to replace all of our current systems. All the solar panels to set up, the wind farms to build, the cars to replace never mind the trucks and planes that can’t hold a battery big enough to run them. There is no way to keep living the way we are and be sustainable.

It’s pretty bleak.

But the Great Filter is only a possibility. Other explanations for the Fermi Paradox exist. Other advanced species could know communication is dangerous and rather hide (unlike us that give a map to our location. That seems like asking for trouble.). Travelling between galaxies may simply not be possible due to the laws of physics, or are just too expensive to be worth it. Or Earth may just be particularly isolated from other habitable planets.

Whether the Great Filter exists or not, what we are doing now just isn’t sustainable. Thanks to climate change and overpopulation, we just won’t have the resources to continue on the way we are for very long. We could stop this way of life now and save something to aid us in setting up sustainable systems for surviving, or continue on until it all collapses under our feet.


If you are interested in The Great Filter and other existential risks I recommend the PodCast “The End of the World” with Josh Clark.

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