The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox.
https://en.wikipedia.org/wiki/Great_Filter
The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, “If life is so easy, someone from somewhere must have come calling by now.”
https://en.wikipedia.org/wiki/Fermi_paradox
Personally I think it’s photosynthesis. Life itself developed and spread but photosynthesis started an inevitable chain of ever-greater and more-efficient life. I think a random chain of mutations that turns carbon-based proto-life into something that can harvest light energy is wildly unlikely, even after the wildly unlikely event of life beginning in the first place.
I have no data to back that up, just a guess.
We’re currently in it. Failing to create a clean, renewable, and scalable energy source powerful enough to run a society that is ever increasing in both population and technology without destroying their only inhabited planet has got to be the most common great filter.
Asteroids strikes, super volcanoes, solar CMEs, and other planetary or cosmetic phenomena that exactly line up in both severity and timing are too rare IMO.
Every society that attempts to progress from Type 1 to Type 2 has to deal with energy production. Most will fail and they will either regress/stagnate or destroy themselves. Very few will successfully solve the energy problem before it is too late.
A filter for sure, but not a great one. Call me optimistic, but I don’t think that will set us back more than 10.000 years. If humanity can survive, society will re-emerge, and we are back here 2-3000 years into the future.
Is +5°C Earth a good place to be? No. Will the majority of humans die? Absolutely. Will the descendants get to try this society thing again? I believe so.
On a cosmic scale 10.000 years is just a setback, and cannot be considered a great filter.