So it appears the stellar carbon cycle does not support the concept that Earth is riding a crest in the probability of habitable planets unless they mean that the number of planets formed peaked right before Earth formed. I'd like to see more details on those calculations. They look related to a lot of things we have discussed here.

If they were looking at planets as old as Earth then the "rise of intelligence as an evolutionary an inevitable outcome theory" dictates there should be civilizations billions of years old unless they are inherently short lived through natural resource limitations, astronomical catastrophes, or self destruction.

Regards,
Mark