Prof Yadvinder Malhi delivers the 2nd School of Geography and the Environment Annual Lecture at the Royal Geographical Society on 12 February 2015. "We live in a new epoch, the Anthropocene, the Age of Us. The defining feature of this age is that sum of human activity (how many we are and what we are doing) has become large compared to the natural processes of the biosphere. How can we measure how "large" we are, and how has our impact on the planet varied throughout human history? I examine this question through the concept of social metabolism, how much energy we use to support our lifestyles, compared to the metabolism of the biosphere. With this concept in hand, we will travel from a world full of hunter gatherers after the end of the last Ice Age, through the dawn of farming, the Roman Empire, the industrial revolution and finally look at prospects for the 21st century. On the way we'll examine whether our cities behave like termite colonies, and whether people walk faster in London than in Oxford. And you'll find out how you are like King Kong …" Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/