For two decades, Daniel Hoornweg, PhD, travelled the world leading the development of sustainable communities. His global expertise in this area provided a pivotal impact on improving the operation and growth of hundreds of cities by optimizing their flow of materials and energy. In 2012, Dr. Hoornweg was appointed Associate Professor and Richard Marceau Chair (formerly Jeffrey S. Boyce Research Chair in Natural Gas as a Transportation Fuel) in the Faculty of Energy Systems and Nuclear Science, a natural next step since energy is central to infrastructure and city development, the core of his distinguished career. He currently holds appointments as the Province of Ontario’s Chief Safety and Risk Officer, and Senior Fellow of the Global Cities Institute at the University of Toronto in Ontario. He also authored the book Cities and Sustainability: A new approach. While serving as an Adjunct Professor at Ontario Tech University for six years, he helped steer the development of more than 300 cities across North America, South America, Africa and Asia as the World Bank’s Lead Urban Advisor on Sustainable Cities and Climate Change. From Washington, D.C., he managed more than 50 infrastructure investment projects with a $3.5 billion investment. He continues as a fellow with the World Bank’s Sustainable Development Network. On secondment from the World Bank, he served as Director of International Development at CH2M Hill Consulting in Toronto, where he assisted the firm’s international business program in India and Nepal. Prior to joining the World Bank, he was Solid Waste Manager with the Government of Bermuda’s Ministry of Works and Engineering. Prior to his impact abroad, Dr. Hoornweg began his career working for local governments on recycling, composting and waste management issues. Fascinated by the ability to affect change at an individual level, as well as city-wide, his motivation for improving communities through waste reduction was spurred by their successes. He held the position of Waste Management Co-ordinator with the City of Guelph, Ontario where he helped launch Canada’s first municipal Green Plan, and introduced the first local government Roundtable on the Economy and Environment. He also served as Recycling Coordinator with the Municipality of Peel Ontario; Well-site Engineer for Schlumberger of Canada in Calgary, Alberta; and Well-site Safety Inspector on Lake Erie with the Ontario Ministry of Natural Resources.