Global Phosphorus supply chain dynamics: Sustainability implications for the 21st century

Abstract: Phosphorus is an essential yet irreplaceable macronutrient for agriculture and thus plays a key role in global food security. Most of the phosphate fertilizers are produced from phosphate rock, a finite mineral resource that is mined and processed at great environmental and social costs. Nonetheless, the present-day phosphorus supply chain transforms this valuable resource also into a major pollutant of water bodies. The research that is presented in this thesis investigated the sustainability challenges of the currently linear phosphorus supply chain and discussed their implications. The main methods used were literature and case study review, semi-structured interviews with stakeholders from the phosphorus sector, stakeholder analysis, systems analysis and system dynamics modelling. Five key messages emerged from this project.First, it is necessary to close the loop throughout the phosphorus supply chain instead of focusing only on end-of-pipeline solutions. Second, in terms of monitoring data, the global phosphorus supply chain is a black box. This poses serious challenges to designing robust policies in food security. Third, industrializing world regions where most of the population growth is expected to occur in the coming decades are increasingly vulnerable to phosphorus scarcity. Fourth, in a business-as-usual scenario, the global supply chain of phosphorus will produce significant amounts of toxic by-products, will have an increasingly negative impact on the climate and will deteriorate the quality of water bodies. Finally, implementing low-input sustainable farming systems, such as agroecology, was shown to have the potentially largest impact in reducing P requirement and in decreasing the negative socio-environmental impacts of the global P supply chain.