The notion of humanity as a geological agent has been around for over a century. But the phenomenal expansion in human impact, and its quantification, largely by Earth-system scientists, is entirely recent. The International Commission on Stratigraphy’s Anthropocene Working Group has been deliberating the Anthropocene and is due to publish its recommendations in 2016. The rest of the world is not waiting and the Anthropocene is generating substantial debate. Three academic journals with an Anthropocene focus have been launched in recent years. Social sciences, the humanities and the media are beginning to explore its meaning and implications. Has the Earth left the relative climatic stability of the Holocene for the more turbulent Anthropocene? Is the Anthropocene the defining concept of our time? Perhaps, but certainly not everyone agrees. This Union Session will bring together geoscientists, historians, social scientists and journalists to explore and debate not only the geological questions, but also the political, cultural and economic implications of living in the Anthropocene and what it means for the future.