Towards global nutrient justice via a circular bionutrient economy

Abstract

Global nutrient flows are profoundly imbalanced. Essential nutrients are extracted, consumed and wasted unevenly across regions, leaving some areas nutrient deficient and others affected by pollution. These imbalances reflect not only biophysical inefficiencies but also structural inequalities in access to fertilizers, sanitation and waste-management infrastructure. In this Perspective, we examine how a circular bionutrient economy can recover nutrients from organic waste streams and redirect them into agrifood systems to promote both sustainability and equity. Global mapping suggests that although approximately 75% of cropland is nitrogen limited and approximately 90% is phosphorus limited relative to locally recoverable nutrients from human and livestock waste, substantial recovery potential exists in many lower-income and middle-income regions, where unmet demand for fertilizer and recoverable waste streams are often co-located. We also compare the features of physicochemical, thermochemical and biological recovery pathways across centralized and decentralized systems and reveal that their benefits depend on context, governance and infrastructure. Although local circular economies have the potential to improve efficiency, reduce pollution and strengthen nutrient sovereignty, they cannot overcome entrenched global nutrient inequalities in the absence of supportive infrastructure, institutions and redistribution mechanisms. Further research is needed to identify which combinations of technologies, governance arrangements and implementation scales can align nutrient recovery with justice goals. Nutrient management is central to global food security, ecosystem health and climate resilience, yet current practices are profoundly inequitable and unsustainable. This Perspective introduces the circular bionutrient economy as a justice-oriented framework for advancing ecological balance and social equity through the recycling of organic waste streams into agrifood systems.