The ISWA 2015 congress comes at a time when many people are looking forward to the next step in the climate debate discussions. Climate, greenhouse gas emissions and energy efficiency have been headlining the (environmental) policy debate for many years now. The congress reaches out to waste professionals, industrialists, policy makers at all levels from around the globe, researchers and entrepreneurs to consider and discuss their role in this upcoming transition. Where do we see niches of promising technologies, local initiatives, new business approaches, alternative policy measures that stimulate progress? How can global trade, shipment and treatment of waste complement the existing flows of raw materials and products? How do we deal with waste and materials in densely populated cities? What is the role of local authorities and world-wide organisations, NGOs, industry and research in the development of new tools and measures? What is the role of the consumer in this growing economy? And how can we come up with a world-wide balanced solution for the materials challenge?