Could this be it?<quoted text>I can remember Sagen talking about SETI not finding "anything" meaning it could be construed that the technical age may not survive, one of the thoughts that drew me to low cost self sustainability
I cant find the quote
"We've arranged a civilization in which most crucial elements profoundly depend on science and technology." - Dr. Carl Sagan
From what I have read of Sagan, he believed that technological civilizations would self-destruct before maturing into spacefaring ones.
"Sagan believed that the Drake equation, on substitution of reasonable estimates, suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations highlighted by the Fermi paradox suggests technological civilizations tend to self-destruct. This stimulated his interest in identifying and publicizing ways that humanity could destroy itself, with the hope of avoiding such a cataclysm and eventually becoming a spacefaring species."
He was very hopeful but still a realist.