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.

A Tale of Two Grains

Food security may be the most important issue we’ll face in the coming decades. With global population on the rise and a changing climate, the future of food is greatly uncertain. These realities have prompted some scientists to start looking at crops that might be well suited to these global changes, foods that are drought resistant and nutritionally rich. That’s where “superfoods” like quinoa and amaranth come in. In this week’s episode, we explore these two crops and their potential to become staple components of our future diets. We first hear from journalist Lisa Hamilton, author of the 2014 Harper’s article “The Quinoa Quarrel.” Then amaranth expert Rob Myers walks us through the relative benefits of quinoa and amaranth, and the challenges to breeding both on a large scale. To wrap it up, Katherine Lorenz shares the story of a nonprofit she founded that uses amaranth to address malnutrition in rural Oaxaca, Mexico.

 

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.