Sunday, March 11, 2012

Peak Phosphorus

Many have heard the expression "peak oil", the point here oil reserves begin to decline. Less well known is "peak phosphorus". Our dwindling supply of phosphorus, a primary component underlying the growth of global agricultural production, threatens to disrupt food security across the planet during the coming century. This is the gravest natural resource shortage you've never heard of.

Farmers treat their fields with phosphorus-rich fertilizer to increase the yield of their crops. However, arge amounts of this resource are lost from farm fields, through soil erosion and runoff. The world's reliance on phosphorus is an unappreciated aspect of the "Green Revolution," a series of agricultural innovations that made it possible to feed the approximately 4.2 billion-person increase in the global population since 1950. This massive expansion of global agricultural production required a simultaneous increase in the supply of key resources, including water and nitrogen. Without an increase in phosphorus, however, crops would still have lacked the resources necessary to fuel a substantial increase in production, and the Green Revolution would not have gotten off the ground.

By 2008, industrial farmers were applying an annual 17 million metric tons of mined phosphorus on their fields. Demand is expanding at around 3 percent a year -- a rate that is likely to accelerate due to rising prosperity in the developing world (richer people consume more meat) and the burgeoning bioenergy sector, which also requires phosphorus to support crop-based biofuels.

Our supply of mined phosphorus is running out. Many mines used to meet this growing demand are degrading, as they are increasingly forced to access deeper layers and extract a lower quality of phosphate-bearing rock (phosphate is the chemical form in which nearly all phosphorus is found). Some initial analyses from scientists with the Global Phosphorus Research Initiative estimate that there will not be sufficient phosphorus supplies from mining to meet agricultural demand within 30 to 40 years. The United States has only 12 phosphorus mines. The supplies from the most productive mine, in Florida, are declining rapidly -- it will be commercially depleted within 20 years.

The geographic concentration of phosphate mines also threatens to usher in an era of intense resource competition. Nearly 90 percent of the world's estimated phosphorus reserves are found in five countries: Morocco, China, South Africa, Jordan, and the United States. (In comparison, the 12 countries that make up the OPEC cartel control only 75 percent of the world's oil reserves.) This fact could spark international tension and even influence how countries attempt to draw their internal boundaries. Many of Morocco's phosphate mines are in Western Sahara, a disputed independent territory that is occupied by Morocco and the site of growing international human rights concerns. The United States exported phosphorus for decades but now imports about 10 percent of its supply, all from Morocco

Increased demand for fertilizer and the decreased supply of phosphorus exports will result in higher prices, significantly affecting millions of farmers in the developing world who live on the brink of bankruptcy and starvation. Rising fertilizer prices could tip this balance. Between 2003 and 2008, phosphate fertilizer prices rose approximately 350 percent.

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