Ecosystem Approaches to Reduce Pollution in Cities

Further reductions in pollution will require new management approaches based on ecosystem concepts. In this paper we examine three case studies that analyze flows of nutrients in urban ecosystems to identify new approaches for pollution management. An analysis of the food chain for the Twin Cities (Minneapolis-St. Paul, Minnesota, USA) is used to examine generation of nutrient pollution in the pre-consumption, consumption, and post-consumption phases. Several scenarios of reduced protein consumption are analyzed for their impacts on agricultural fertilizer requirements. Reductions of up to 40% of fertilizer N are possible with small to moderate dietary adjustments. We then examine phosphorus inputs to urban residential landscapes to show how a newly enacted lawn P fertilizer restriction has reduced P inputs by 90%. The third case study examines fluxes of carbon, nitrogen and phosphorus fluxes through suburban households. This study shows that “high-consumption” households may have 3-4 times higher carbon and nitrogen fluxes than “low-consumption” households. Developing pollution reduction policies based on ecosystem concepts will require new research that integrates social and biophysical sciences.