There’s a lot of debate about the idea that the global changes brought about by humans define a new geological epoch, dubbed the Anthropocene. Should such an epoch be added to the official geological time scale? If so, what aspect or aspects of anthropogenic change should be used, and exactly where do we place the golden spike that will define the base of the Anthropocene? Such questions come under the purview of the International Commission on Stratigraphy, whose current secretary general is our guest in this episode.  Phil Gibbard is Emeritus Professor of Quaternary Palaeoenvironments at the University of Cambridge.  In 2009, he was a founding member of the Anthropocene Working Group tasked by the International Commission on Stratigraphy to examine the status, hierarchical level, and definition of the Anthropocene as a potential new formal division of the Geological Time Scale.  He explains that no consensus on the Anthropocene has been reached, and it remains controversial as to whether there is even a need for such an epoch at all. Go to geologybites.com for podcast illustrations.  And if you're enjoying the series, I'd be grateful if you could rate the podcast and leave a review.