Systems Perspectives on Modelling and Managing Future Anthropogenic Emissions in Urban Areas Nitrogen, Phosphorus and Carbon Studies in Stockholm, Sweden

Sammanfattning: Managing anthropogenic emissions in urban areas is a major challenge in sustainable environmental development for cities, and future changes and increasing urbanisation may increase this challenge. Systems perspectives have become increasingly important in helping urban managers understand how different changes may alter future emissions and whether current management strategies can efficiently manage these emissions. This thesis provides some systems perspectives that have been lacking in previous studies on modelling and managing future anthropogenic emissions in urban areas. The city of Stockholm, Sweden, was selected as the study site and studies about nitrogen, phosphorus and carbon were chosen, given world-wide urban eutrophication and global concerns about climate change. A substance flow analysis (SFA) structured model, comprising a source model coupled with a watershed model in an SFA structure, was developed to investigate future nutrient loading scenarios under various urban changes in small urban lake catchments. The results demonstrated that climate change potentially posed a greater threat to future nutrient loads to a selected lake catchment in Stockholm than the other scenarios examined. Another SFA-based study on future phosphorus flows through the city of Stockholm indicated that the best management option may depend on the perspective applied when comparing future scenarios of phosphorus flows and that both upstream and downstream measures need to be considered in managing urban phosphorus flows. An evaluation approach for examining current management plans and low-carbon city initiatives using the Driving forces-Pressure-States-Impact-Response (DPSIR) framework, was formulated. With such an evaluation approach, investigation of how well selected plans cover different aspects of the DPSIR framework and whether root causes and systematic measures are highlighted is possible. The results revealed that the current low-carbon city initiative in Stockholm falls within pressure-based, driver-orientated plans and that technical, institutional and cognitional measures are generally well covered.