What caused 5 previous mass extinctions of species? Scientists say we are in the 6th one now.
Dr. Andrew Glikson of Australian National University studied the rocks and the timelines. He's also an expert on asteroid hits.
A deep 44 minute interview with a world-class climate scientist and geologist - on what the past says about our future under climate change.
Dr. William Calvin of the University of Washington is author of over a dozen books, including "Global Fever, How to Treat Climate Change" and A Brain for All Seasons, Human Evolution and Abrupt Climate Change." We have a short chat, about how the ice ages shaped our brains, and recent signs of climate shift.
Followed by his introduction in a speech at the University of Victoria, by Dr. Colin Campbell of the Sierra Club. Insightful on the way climate shapes our species, and all species.