Lewis is Executive Director of Hot or Cool Insitute. He is a political economist with an interest in institutions and policies, and the fair allocation of resources and opportunities for collective wellbeing within ecological limits.
Lewis has served as Executive Director of SEED, founded as a UN partnership at the 2002 World Summit on Sustainable Development to promote entrepreneurship for sustainable development. Prior to that, he was Director for Sustainable Consumption and Production at the Institute for Global Environmental Strategies in Japan. He has consulted with organizations including United Nations agencies, the Asian and African Development Banks, the European Commission, the Association of Southeast Asian Nations (ASEAN), and has served as technical or science-policy adviser to several national government delegations, including Finland, Japan, Sweden, Indonesia, Hungary.
Lewis is a Full Member of the Club of Rome, and a Transformational Economics Commissioner with the Earth4All project, and is Board member of several organisations.
Lewis has an M.Sc. Sustainable Resource Management (Technical University Munich, Germany) and a Ph.D. Political Economy (University of Helsinki, Finland).