More than 200 million years ago, a cataclysmic event known as the Permian extinction destroyed more than 90% of all species and nearly 97% of all living things. Its origins have long been a puzzle for paleontologists, and during the 1990s and the early part of this century a great battle was fought between those who thought that death had come from above and those who thought something more complicated was at work.

Paleontologist Peter D. Ward, fresh from helping prove that an asteroid had killed the dinosaurs, turned to the Permian problem, and he has come to a stunning conclusion. In his investigations of the fates of several groups of mollusks during those extinctions and others, he discovered that the near-total devastation at the end of the Permian was caused by rising levels of carbon dioxide leading to climate change. But it’s not the heat (nor the humidity) that’s directly responsible for the extinctions, and the story of the discovery of what is responsible makes for an fascinating, globe-spanning adventure.

Brown Bag Lecture Series; Center for Student Engagement & Leadership; and Arts, Culture, and Civic Engagement, Apr. 11, 2013

In honor of Earth Month: Peter D. Ward, Ph.D., is a paleontologist and professor of Geological Sciences at the University of Washington. Ward specializes in the Cretaceous-Tertiary extinction event (the one that killed the dinosaurs), the Permian-Triassic extinction event, and mass extinctions in general. He was elected as a fellow of the California Academy of Science in 1984 and has been nominated for the Schuchert Medal, an award of the Paleontological Society. Ward has written many books including Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future and The Flooded Earth: Our Future In a World Without Ice Caps.