Helga Weisz is an industrial ecologist. Her research focus is on the socially organized extraction of raw materials and energy, its transformation into goods and services, its use and final disposal to the environment as waste, emissions and heat, which, collectively, define the social metabolism. The transition from a biomass based agrarian towards a fossil fuel based industrial socio-metabolic regime has the dual consequence of bringing large parts of the population out of extreme poverty while creating global environmental change including climate change. Transforming the industrial metabolism to reduce its environmental and resource impacts, while maintaining its function for human well-being, is therefore a crucial challenge for sustainability. Main research areas are material and energy flow analysis, stocks and flows dynamic of the built environment, physical and environmental input-output analysis, society-nature co-evolution, socio-ecological theory, industrial and urban metabolism, integrated vulnerability assessment and the application of complex network analysis to social metabolism.