On this installment of ST, we speak by phone with Anthony Barnosky, a Professor of Integrated Biology at UC-Berkeley and a leading scientist specializing on how global change affects biodiversity and ecosystem function. His latest book, "Dodging Extinction," is the focus of our conversation today; it's been touted by Library Journal as a "superior synthesis of recent research from many scientific disciplines...[and an] eloquent book [that] could serve as a model for how scientists should write for non-specialists about the critical environmental challenges of our time." As Barnosky explains, over the past 500 million years or so -- the time during which complex life has existed on Earth -- there have been five massive extinction events, long-form catastrophes by which three-quarters or more of all species on the planet have been extinguished. Barnosky argues that global warming and other environmental crises caused by human beings are now bringing about a so-called Sixth Extinction -- and so his book explores both the science behind this environmental emergency and the extraordinary changes required immediately to avoid one of the greatest disasters in the history of life on earth. As the science journalist and blogger Annalee Newitz noted of this volume, when talking about the "Best Science Books of 2014" on PRI's Science Friday: "Beautifully written.... A very learned book, but it's very approachable and fun.... Anyone who is interested in the future of the planet or loves animals should check this one out."