. >> hi everyone, i'm sarah mathers, publishing manager at Ãbi'd like to welcome yo

. >> hi everyone, i'm sarah mathers, publishing manager at Ãbi'd like to welcome you to today's authorsin conversation series. these are made possible by more than 200 sponsors and more than 1000 local Ãa special thanks to the arizona daily star, university of arizona in tucson medical center. the festival three present expenses. today's conversation is presented by western notion Ãb and sponsor of the national experience pavilion at the tucson festival of books. to keep up-to-date with the festival live events and sign up for the festival newsletter visit tucson festival books.org. joining me today is bryan walsh kebab ryan is. he signed the award-winning egocentric blog and has reported for more than 20 countries on science and environmental stories like stars, global warming at extension. he is the founder and editor of technology and science 10 his book is "end times". bryan, welcome, thank you for being with us. >> this book is about existential risks, risks which could illuminate all of humanity or enough of humanity survivors would not be able to rebuild society to what it is now