According to the general consensus of scientists, the existence of advanced intelligent life in the universe is fairly probable. However, our civilization is the only one that has ever been detected. To account for this Robin Hanson hypothesized that the failure to find any extraterrestrial civilizations implies that something is wrong with the argument. He proposed the existence of a “great filter” that acts to reduce the relatively large number of places where intelligent life might arise to the tiny number of civilizations that have actually been observed. If this is true then we may very well be headed toward imminent extinction. One of the main factors in this depends on whether or not our society is inherently self-destructive.
Without knowing exactly what to expect as we continue to evolve, a great filter could express itself as any kind of challenge or threat that would consistently eliminate the species. One of the most likely candidates for this is man-made climate change. Guy McPherson even goes so far as to speculate that humans will be extinct by no later than 2030 as a result of global warming. This seems far too soon to me, but either way, the thing about a great filter is timing. Logic dictates that there are only two potential scenarios that could arise from the great filter hypothesis. One of these would make humans incredibly special while the other would mean that we are doomed no matter what. The former would indicate that the great filter(s) must have already happened while the latter would mean a great filter is yet to come. So, which is it?
If the filter is in our past then we would necessarily be the first advanced civilization in the universe. Granted, it may very well just turn out that life is rare, but that seems very doubtful to me. More than likely, life is incredibly abundant in the universe. In fact, it should exist anywhere that the conditions are right, based on the prevalence of organic compounds in space. Then again, maybe mass extinctions just always happen. As it is, life on Earth has already survived five mass extinction events and is in the midst of the sixth as you read this. The question is, will we live through it or not? Plus, how common are extinction level threat events, and how many different forms can they take?
This brings us to the second scenario for the great filter, which places it in the future. If this is the case then the event would be orders of magnitude more dangerous than anything we have already encountered. If a great filter does, in fact, lie ahead of us, then it has to be incredibly lethal to have destroyed every other advanced civilization in the galaxy. This is likely to be completely unpredictable. Then again it could easily be something we already possess. Whether it might be nanobots or AI gone awry, nuclear missiles, a meteor, or anything else for that matter, a future great filter would mean that we will go extinct no matter what. The question is will we remain extant for thousands, millions, or even billions of years?
Hell, maybe there is no filter, or maybe it isn’t really that great after all. What if it’s only just really good, but not quite great? Regardless, if our species is ever reduced to an insufficient number of breeding pairs then we will surely go extinct, however, if we don’t all die out really soon then we will likely continue on with our explosive population growth until the turn of the century. As it currently stands, we should reach peak population for this planet at around 11 billion people by the year 2100. As this occurs, we will likely develop from a Type 0 civilization to that of Type 1, becoming an interplanetary species which will then improve our odds of survival even further. Only time will tell though.