Will Steffen is an American chemist. He was the executive director of the Australian National University (ANU) Climate Change Institute and a member of the Australian Climate Commission until its dissolution in September 2013. From 1998 to 2004, he was the executive director of the International Geosphere-Biosphere Programme, a co-ordinating body of national environmental change organisations based in Stockholm. Steffen is one of the founding Climate Councillors of the Climate Council with whom he frequently co-authors reports and speaks in the media on issues relating to climate change and renewable energy.