Towards sustainable phosphorus use in the European Union: Evaluating resource cap scenarios

Phosphorus is an essential nutrient for food production, yet the phosphorus planetary boundary has already been surpassed. Stronger policies to manage phosphorus are needed to reduce phosphorus application and associated impact. One such proposed policy is to introduce a resource cap to limit use and ensure fair and sustainable phosphorus consumption. This article is the first to investigate a phosphorus consumption cap, with a case study of the European Union outlining six different scenarios for distributing phosphorus allowances between member states. It was found that the most promising approaches would be to distribute phosphorus-use allowances based directly on the planetary boundary framework, with cap distributions based on current consumption and environmental impact levels being strong alternatives. However, there are competing plausible scenarios suggesting diametrically opposed outcomes, such as a vastly increased or reduced allocation of phosphorus to Austria, Greece and Italy based on the scenario considered. Practical implementation will require significant trade-offs between states. This article suggests novel approaches to distributing phosphorus allowances and demonstrates that resource caps can be an effective management option for phosphorus if political consensus on equity and a fair distribution can be reached.