Pascal Lee on why microbial worlds might be common but intelligent civilizations exceedingly rare

On October 23, 2013, Pascal Lee, Senior planetary scientist at the SETI Institute, the chairman of the Mars Institute, and the director of the NASA Haughton-Mars Project at NASA Ames Research Center, spoke at a public event for a Peter Wall Institute International Roundtable entitled Time and Life in the Universe.

Are we alone in the universe? Are there other intelligent civilizations in our galaxy? Science fiction often portrays space as populated by many other intelligent species. But are there truly myriad alien societies out there? A pragmatic analysis of lessons learned from a wide range of scientific fields, from astrophysics to planetary sciences, geology to microbiology, anthropology to archaeology, suggests that an outcome such as us, an intelligent civilization, while the result of natural processes, might be exceedingly rare. Could we possibly be alone in our galaxy? If so, what might be our cosmic future? Will we achieve interplanetary travel? What about interstellar travel? And where would we (boldly) go?