William Rees is a Professor in the School of Community and Regional Planning at the University of British Columbia (UBC). His teaching and research emphasize the public policy and planning implications of global environmental trends and the necessary ecological conditions for sustaining socioeconomic activity. Much of his work is in the realm of ecological economics and human ecology. He is best known in this field for his invention of 'ecological footprint analysis', a quantitative tool that estimates humanity's ecological impact on the ecosphere in terms of appropriated ecosystem (land and water) area. Dr. Rees was awarded a UBC Killam Research Prize (1996) in acknowledgement of his research achievements. William is a Fellow of Post Carbon Institute.