Phosphorus is an essential element. We consume phosphorus through food produced with fertilizers, and population growth and changing diets are increasing demands for the finite resource of phosphate rock. Around 191 Mt of phosphate was mined in 2011, yielding 83.3 Mt of phosphorus. More than 80% ended up as agricultural fertilizer.
Phosphorus extraction, processing and use today involve substantial losses – from agriculture through soil erosion and run-off, food waste, manure and sewage sludge. This wastes a limited resource and contributes to severe environmental impacts such as eutrophication of freshwater ecosystems and development of dead zones in oceans. Sustainable phosphorus governance requires mapping stocks and flows to identify key points where we can minimize dissipation and increase recycling.
While loss of phosphorus is inevitable in mining, processing and use, the dissipated phosphorus would be more or less accessible for subsequent recycling, depending on the sink. Phosphorus recycling spans diverse scales and contexts: from farms to households to megacities - where food is consumed away from production; from simple household and livestock waste composting to complex recovery from sewage, food and industrial waste products; and from large-scale, advanced facilities in industrialized countries to small-scale efforts in developing countries, where direct local-level recycling such as urine diversion may be used.
A critical challenge for sustainable phosphorus use is to make phosphorus recovery economical, reliable and predictable while ensuring that recycled phosphorus products will not have adverse health or environmental impacts. It is therefore crucial to manage phosphorus stocks and flows through a systems-based approach, integrating the issues of dissipation, eutrophication and recycling. The system is affected by current and potential markets, quality and price of products, process costs, available and future technologies, institutional structures and public perception and behavior. Stakeholders involved are diverse, including industries creating waste streams and others focusing on phosphorus recovery such as farmers, governmental agencies, public environmental and health organizations, researchers and agricultural and health NGOs.
Technologies already exist to recycle phosphorus from different sources. In Japan, for example, a variety of potential phosphorus resources, including food waste, sewage sludge, steelmaking slag, and other industrial wastes, could provide approximately 240 kt per year, which is comparable to the phosphorus demand for fertilizer of around 284 kt per year; hence, an appropriate nation-wide recycling strategy could potentially provide the majority of phosphorus required for agricultural production within the country. However, only a small percentage of recoverable phosphorus is recycled at the moment, while a significant proportion dissipates to the environment. The reasons include weak economic incentives, insufficient regulation, technical obstacles and poor anticipation of unintended impacts. Minimizing losses and increasing recycling rates, as well as reducing environmental impacts of phosphorus dissipation, requires a better understanding of the social, technological and economic rationale as well as the interrelations between nutrient cycling and ecosystem stability. It also calls for new social business models integrating innovative technologies, corporate strategies and public policies. That requires intensive collaboration between different scientific disciplines and, most importantly, among key stakeholders, including industry, farmers and government agencies.
Among areas where human activity is leading to global change, including climate, stratospheric ozone depletion, and biodiversity loss, phosphorus is not yet addressed successfully through a policy framework. There is no equivalent here of the United Nations Framework Convention on Climate Change, the Montreal Protocol, or the Convention on Biodiversity. That is partly because various stakeholders with different views and interests are involved in the phosphorus supply chain, ranging from exploration, mining, and shipping to use and recycling. That would make it particularly difficult to establish a system for collecting and sharing knowledge concerning natural and social systems, and coordinating responses among the stakeholders.
However, a series of regional initiatives may show how to establish effective mechanisms for promoting coordination and collaboration among stakeholders. In Japan the Phosphorus Recycling Promotion Council was established in December 2008 - with experts from academia, industry, and the government - to design and implement national strategies for socially robust phosphorus recycling. The Dutch Nutrient Platform was founded in January 2011, which eventually contributed to launching the European Phosphorus Platform in March 2013 to facilitate dialogue, raise awareness and trigger actions to address the phosphorus challenge. It emphasises the implications for ensuring food security, geopolitical stability and environmental sustainability in the context of a resource-efficient Europe. In North America, the Phosphorus Sustainability Research Coordination Network has been established since 2013 to share knowledge and expertise on various dimensions of the global phosphorus system. It includes farmers and growers, food processors, fertilizer producers, waste managers, water quality managers, regulators, and legislators.
These efforts may point the way forward for collaborative knowledge-creation, target-design, and process-implementation for sustainability innovation, all in a transdisciplinary framework. There still remain serious challenges, including how to facilitate serious engagement and fruitful collaboration among stakeholders, what types of joint initiatives and networking contribute to identifying desirable goals and targets and developing complementary skills and capacities, and what factors promote their successful implementation. But from their different starting points each of these initiatives offers something to build on. Those involved in these regional initiatives have started to communicate with each other through international conferences such as the Sustainable Phosphorus Summit held in Montpellier, France in September 2014, and the forthcoming Sustainability Science Congress in Copenhagen is also expected to provide an excellent opportunity for discussing this pressing challenge at the global level.
Yarime, Masaru, Cynthia Carliell-Marquet, Deborah T. Hellums, Yuliya Kalmykova, Daniel J. Lang, Quang Bao Le, Dianne Malley, Kazuyo Matsubae, Makiko Matsuo, Hisao Ohtake, Alan Omlin, Sebastian Petzet, Roland W. Scholz, Hideaki Shiroyama, Andrea E. Ulrich, and Paul Watts, "Dissipation and Recycling: What Losses, What Dissipation Impacts, and What Recycling Options?" in Roland W. Scholz, Amit H. Roy, Fridolin S. Brand, Debbie T. Hellums, and Andrea E. Ulrich, eds., Sustainable Phosphorus Management: A Global Transdisciplinary Roadmap, Dordrecht: Springer, 247-274 (2014).