Ugo Bardi, is a lecturer in physical chemistry at the University of Florence, in Italy. He is engaged in research on sustainability and energy, with a special view on the concept of circular economy and on the depletion of mineral resources. He is a prominent leader in the engineer, science and policy makers movement for renewable energy transition, and a member of the Club of Rome, an international think tank dedicated to sustainability. Dr. Bardi’s contribution to the dissemination of scientific research in sustainability and climate science includes his influential blog “Cassandra’s Legacy”. He is the author of numerous papers and several books on resilience and sustainability.