I have a Great Filter related thought which doesn't address your question directly but, hey, it's the Open Thread.

My thesis here is that the presence of abundant fossil energy on earth is the primary thing that has enabled our technological civilization, and abundant fossil energy may be far less common than intelligent life.

On top of all the other qualities of Earth which allowed it to host its profusion of life, I'll point out a few more facts related specifically to fossil energy, which I haven't seen in any discussions of Fermi's Paradox or the Great Filter.

• Life on Earth happens to be carbon-based, and carbon-based life, when heated in an anoxic environment, turns into oil, gas and coal.

• Earth is roughly 2/3 covered in oceans (this figure has varied over geologic time), a fact with significant consequences to deposition of dead algae, erosion, and sedimentation.

• Earth possesses a mass, size, and age such that the temperature a few kilometers below the surface may be hundreds of degrees C, while the surface temperature remains "Goldilocks."

• Earth has a conveniently oxidizing atmosphere in which hydrocarbons burn easily, but not so oxidizing that it prevents stable carbon-based life. Quite a narrow window, really.

• Life has existed on Earth for billions of years, and thus algae and other life forms have been dying in oceans and swamps and accumulating subsurface hydrocarbon source material, for billions of years.

Put all this together and realize that the formation of oil, gas, and coal happens only in rare and specific circumstances even on Earth. We seem to have a lot of these resources today, but it took billions of years for them to accumulate in the quantities we now find.

If any one of the above facts were not true, we would not have fossil energy - coal, oil, gas, plastics, lubricants - we would not have an industrial revolution, and we would not have a technological civilization.

Many of the facts on the above list have to be true simply to enable fire, as in, wood fire, imagine what human history would look like if the oxygen content of Earth's atmosphere was too low to sustain wood fire?

Anyways, maybe people have discussed this before, but I wasn't able to Google anything up.