Aerial view from 800 feet of waste filling an impoundment at a Lakeland, Florida, phosphate mine. Photography by J. Henry Fair / onearth.org

By Fred Pearce
7 Jul 2011 If you wanted to really mess with the world’s food production, a good place to start would be Bou Craa, located in the desert miles from anywhere in the Western Sahara. They don’t grow much here, but Bou Craa is a mine containing one of the world’s largest reserves of phosphate rock. Most of us, most days, will eat some food grown on fields fertilized by phosphate rock from this mine. And there is no substitute. […] Not many people would call phosphate a critical issue or one with serious environmental consequences. But even leaving aside the resource politics of the Sahara, it is an absolutely vital resource for feeding the world. It is also a resource that could start running low within a couple of decades — and one we grossly misuse, pouring it across the planet and recycling virtually none of it. […] Phosphorus is one of the building blocks of all life. Every living cell requires it. Plants need phosphorus to grow as much as they need water. Many soils do not have enough to meet the voracious demands for phosphorus of the high-yielding crop varieties of the Green Revolution. But we can provide more by mining phosphate rock and turning it into fertilizer to spread on the land. It takes one ton of phosphate to produce every 130 tons of grain, which is why the world mines about 170 million tons of phosphate rock every year to ship around the world and keep soils fertile. Currently, only about 15 percent of that comes from mines in the Western Sahara and Morocco. But the only other large producers, the U. S. and China, mostly keep supplies for their own use. So Morocco is by far the biggest contributor to international trade, with more than half the total business. The people of India, the world’s largest importer, would be starving without Morocco’s phosphates. Brazil’s agricultural boom would never have happened otherwise. Even more critically in the longer term, the U.S. Geological Survey says that of the 65 billion tons of the world’s known phosphate rock reserves — and the estimated 16 billion tons that might be economic to mine — almost 80 percent is in Western Sahara and Morocco. Add in China’s reserves, and the figure rises to almost 90 percent. The U.S., with 1.4 billion tons, is close to running out. You can see why agronomists are starting to get worried. The world is not about to run out of phosphate. But demand is rising, most of the best reserves are gone, and those that remain are in just a handful of countries. Dana Cordell of Linkoping University in Sweden, who runs an academic group called the Global Phosphorus Research Initiative, says we could hit “peak phosphorus” production by around 2030. […] The other key ingredient needed to fertilize modern high-productivity farm soils is nitrogen. We know how to “fix” nitrogen from the atmosphere. If the German chemist Fritz Haber hadn’t come up with his process in 1908, there wouldn’t have been a Green Revolution — and there wouldn’t be 7 billion people on the planet today. The nitrogen produced by this process is estimated to be directly responsible for feeding 3 billion of us. But there are no new sources of phosphate. We continue to mine the rock — or we starve. Phosphate strip mines are environment wreckers. They produce around 150 million tons of toxic spoil a year. Their massive draglines, huge slurry pipes, and mountainous spoil heaps dominate the landscape for tens of miles in key mining zones, whether in the North African desert or in Florida, a state that still provides three-quarters of American farmers’ phosphate needs. The world’s largest mine is at Four Corners in an area known as Bone Valley in central Florida. The Four Corners mine covers 58,000 acres, an area five times the size of Manhattan. It is owned by Mosaic, a company recently spun off from agribusiness giant Cargill. Next door is the world’s second-largest mine, South Fort Meade. But South Fort Meade is living on borrowed time — its expansion plans are being opposed by local groups, and unless it can expand, the mine will have to close. As the drag mines move south in Florida, anger has been growing about the environmental impacts. A million tons of mine waste, containing lows levels of radioactivity, are already piled up at dump sites around the state, and disputes are growing over promised mine cleanups. Rivers have dried up, and settling ponds have leaked. […] While nitrogen pollution tends to get top billing as a cause of eutrophication, cyanobacteria can often abstract nitrogen from the air. David Schindler, of the University of Alberta in Edmonton, and others have argued that limiting phosphorus pollution is the key to eliminating eutrophication. […]

Phosphate: A Critical Resource Misused and Now Running Low via The Oil Drum