Mass flows form the very basis of our economy and society. Mass flows are about the global production of feed and food, the extraction of natural resources like fossil fuels and minerals, their transport to industrial sites and conversion into materials and products and finally the use and disposal of these products. Increasingly, infinite economic growth faces finite natural resources and ecological impacts that exceed the so-called planetary boundaries. Vice versa there is strong need to fulfil our global needs and wants, with radically fewer natural resources, materials and environmental impacts. In this course you will study mass flows on different scales (e.g. products, nutrients, economies), you will explore tools that are used to analyse and quantify mass flows and you will be introduced to frameworks like industrial ecology, circular economy, planetary boundaries, footprints and life cycle analyses. Upon completion of this course you have gained both theoretic and practical knowledge on how to identify, analyse and minimize the ecological impacts of mass flows.