Preface All living organisms depend on phosphorus. Indeed, phosphorus is part of every living cell. No other element could emulate or stand in for phosphorus in countless physiological and biochemical cell processes. Crop production therefore relies on a plenteous P supply. The phosphorus content of fodder and foodstuffs likewise has to be sufficient. However, local eutrophication caused by too much of the element in the environment can disrupt ecosystems. This phenomenon occurs in the Netherlands, where large quantities of phosphorus are imported with raw materials for cattle feed and artificial fertiliser. Much of this accumulates in the soil, from where it leaches and drains into surface water and groundwater. While accumulated phosphorus in the soil contributes poorly to crop food supplies, when it leaches and drains away it is wasted. Depletion must then be added to the environmental damage caused. Depletion is a serious matter, because the phosphate supply is finite. There is a growing awareness worldwide of the need to deal far more efficiently with phosphorus. This need was the immediate background to this study, which aimed to identify and quantify global phosphorus supplies and demand, now and in the future. The authors have backgrounds in geochemistry and mineralogy. They estimate that current, proven phosphorus supplies will be exhausted somewhere between 2040 and 2070, with as yet unidentified but presumed phosphorus reserves running out between 2100 and 2150. Much of the considerable bandwidth in the time horizon is explained by uncertainties surrounding the future demand for phosphorus to support food production for the growing global population, and biomass for energy and other applications. If phosphorus prices rise above current levels, exploitable supplies will increase correspondingly. For instance, a doubling of phosphorus prices translates into sufficient supplies for several centuries. Pagina 4

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