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?