Earth in Human Hands

“What if life isn’t something that happens *on* a planet, but is something that happens *to* a planet? What if the planet itself is alive?” Thus begins one of the many intriguing thought exercises in astrobiologist David Grinspoon’s new book, Earth in Human Hands (available Dec. 6, 2016). David has long been a friend of the show, in large part because he possesses a unique ability to bring the geologic imagination to life. His approach to the Anthropocene draws extensively from deep time and close observations of other planets to see what we might learn about our uncomfortable situation here on Earth. If the Anthropocene is part of the geologic time table (it is), and if the geologic time table is largely defined by life (it is), then does our current situation mean something much broader in terms of planetary evolution? David chats with GenAnthro producer Miles Traer about the new book, mind-bending perspectives on time, and why the Anthropocene hopefully marks the start, and not the end, of something quite spectacular.

THIS EPISODE WAS PRODUCED BY LESLIE CHANG, MIKE OSBORNE, AND MILES TRAER.

On the Precipice

Sometime in the near geological future, the landscape of life on earth as we know it will be transformed. It’s a mass extinction, and it’s only happened five times before in Earth’s history. There have been severe ice ages, perplexing loses of oxygen from our oceans, massive volcanic eruptions, meteor impacts. And now, we’re on the precipice of a sixth mass extinction… and it’s nothing like our planet has ever seen before. In Season 8’s final episode, producer Miles Traer dives into the sixth mass extinction: Are we in it? What can the previous mass extinctions teach us about what’s going on today? And how is it going to affect not just our lives, but the long term trajectory of human evolution? Paleobiologist Jonathan Payne takes us back into the geologic past and searches for biological patterns hidden in the rock record. In the previous moments of ecological chaos, Payne finds a surprising trend that no longer holds true today. Then, biologist Rodolfo Dirzo takes us into the heart of complex ecosystems to find out why large animals are so crucial for their health and survival. Based on experiments in the tropics and in East Africa, he shares what he’s seen when those large animals disappear.

THIS EPISODE WAS PRODUCED BY LESLIE CHANG, MIKE OSBORNE, AND MILES TRAER.

Are we alone in the universe?

How did life begin on Earth? Curiously, scientists often search for the answer on other planets or moons in our solar system. After all, if we want to see whether our theories are right, we need to find another example of life somewhere. The search has taken us to some strange places seemingly frozen in time that give us hints to what Earth looked like billions of years ago when life first appeared in the geologic record: places like Mars that show evidence of fossil oceans, and places like Saturn’s moon, Enceladus, that show evidence of liquid water oceans containing organic molecules hidden under an icy crust. NASA astrobiologist Chris McKay has been a member of missions that sent spacecraft to these and other places in search of that elusive other example of life in the universe. He recently sat down with producer Miles Traer to discuss the best current theories for the origin of life on Earth, why Antarctica is a lot like one of Saturn’s moons, the challenges of collecting data from other planets, and the reasons we’re captivated by the question, “Are we alone in the universe?”

THIS EPISODE WAS PRODUCED BY LESLIE CHANG, MIKE OSBORNE, AND MILES TRAER.

Environmental Icon David Suzuki

This week we bring you an intergenerational conversation featuring David Suzuki, who is a Canadian scientist, activist, and media figure. Since the 1970s, Suzuki has hosted both radio and television shows about the natural world and environmental issues. A self-described “elder,” Suzuki shares his views and long-term perspective on environmentalism with our producer Mike Osborne. Their wide-ranging conversation spans climate change, energy, shortfalls of the environmental movement, and the evolving relationship between humans and Earth’s ecosystems.