Gabe Bowen, professor of geology and geophysics at the University of Utah, discusses how geoscientists have mapped changes in atmospheric CO2 over past 66 million years. (0:51)
Then, John Wells, co-founder and co-host of Cool Science Radio, talks about the last decade hosting this science and technology show — what he has learned and loved as he departs the show for new endeavors. (25:33)
