The public often sees phosphorus in terms of its negative environmental connotations. Labels on detergents reading "phosphate free" highlight this tendency alongside the global lament on the impacts of phosphate mining in countries like Nauru in the central Pacific. Yet phosphorus is essential for all living cells as it is a key elemental constituent of Adenosine Triphopshate (ATP) -- the molecule that acts as currency for energy transfer. Phosphorus is thus a limiting element for life and it is for that very reason that it has been so prized for fertilizer production to make its way into the food chain. Indeed, the paucity of observed life in the universe thus far was hypothesized to be linked to the scarcity of phosphorus on planets by the great science and science-fiction writer Issac Asimov.
Phosphate mining on the remote pacific island of Nauru ravaged the landscape, but also helped propel the food production in Australia and many other parts of the world in the twentieth century. I had an opportunity to visit Nauru in 2015 and co-authored on an article published in Ambio a couple of years later. The goal of this article was to consider ecological restoration of Nauru's phosphate mining region so that this resilient little country could "bounce back better" -- a term that has acquired new currency in age of COVID-19. As Nauru's land is restored through a strategy of diversification, we should also consider the supply chain for phosphorus and ways to harness the element more sustainably.
More than 70% of the world's rock phosphate for fertilizer production is now found in Morocco and the disputed territory of Western Sahara. Just before leaving office, former President Trump of the United States recognized Morocco's claim to all of the Western Sahara region in exchange for the country's resumption of diplomatic ties with Israel. The Biden administration has not indicated a reversal of this policy and de facto Morocco will likely remain in control of much of the phosphate mining region. The concentration of economically viable phosphate deposits with one country should be a concern as the element is key for global food security. At the same time if there is good governance and responsible mining of these reserves, they could be a source of poverty alleviation in the phosphate mining regions of the Sahara.
To address this reliance on mined phosphorus, research on recycling of phosphorus from effluent and a variety of other sources is now gaining greater attention. However, cost factors are still very high as compared with mined phosphorus. Far greater research on biotic mechanisms for harnessing phosphorus, including from phosphine gas, need to be considered. Research on phosphine's role in the global phosphorus cycle is drawing increased attention by researchers. Indeed, greater bioavailability of nitrogen (N), phosphorus (P) and potassium (K) in the Anthropocene has strongly impacted terrestrial plant communities. We are thus left with a paradox that despite the limiting scarcity of phosphorus for human food security, it has become more diffusely abundant through human agricultural industries and waste systems.
Global efforts to better manage phosphorus cycles need to be coordinated with concerted investment in research and monitoring of phosphorus flows. Efforts such as the Sustainable Phosphorus Alliance based at Arizona State University are a promising sign that the urgency of our dependence on phosphorus is being recognized. Two of the key research founders of this alliance Jim Elser and Phil Haygarth have just published an authoritative book for a broad general audience that should be read by policy-makers worldwide -- particularly at the United Nations Environment Assembly which meets later this month in Kenya. World leaders should consider the words of President Franklin D. Roosevelt as the United States was recovering from the Great Depression in 1938:
"The disposition of our phosphate deposits should be regarded as a national concern....The situation appears to offer an opportunity for this nation to exercise foresight in the use of a great national resource heretofore almost unknown in our plans for the development of the nation.”
Roosevelt spoke those words before the advent of major international environmental treaties -- his tone was thus nationally focused. In this day and age, his prescient words should be a call to global action on more effective international management of this precious element.
Saleem H. Ali is Blue and Gold Distinguished Professor of Energy and the Environment at the University of Delaware (joint tenured appointments in Geography and the Joseph Biden School of Public Policy); Senior Fellow at Columbia University's Center on Sustainable Investment; and a Professorial Research Fellow at the University of Queensland (Australia). He is also a member of the United Nations International Resource Panel and the Scientific and Technical Advisory Panel of the Global Environment Facility. Twitter @saleem_ali