Bat guano, bones, rock mining, and clean water

7 Jul

Yale e360 has an article today about the importance and future scarcity of phosphate, a key mineral in fertilizers and therefore essential to our ability to feed ourselves.  Read the article and you can learn that phosphate, which is a key ingredient in animal bones and supplies phosphorous to plants, has long been used to boost fertility in agriculture and it is now inseparable from modern farming practices.  During the era of the British empire the mineral was shipped around the world in the form of bones to be ground into bonemeal, and later it was shoveled up from huge historic piles of bat and bird guano.  Some tiny islands in the Pacific, that were essentially just bird colonies, were leveled almost to the ever-encroaching tide line as their guano was mined and shipped away.  Now, phosphate is mined largely from deposits of mineral-rich rock, with most of the world’s exports coming from Morocco.  Other significant deposits are in the US and China, which use them mainly for their own use and don’t export them.  This brings me to this interesting passage, at the bottom of the article:

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.

Last year, the local chapter of the Sierra Club went to court to block Mosaic’s plans to extend the life of the South Fort Meade mine by expanding its footprint. The group is concerned about the fate of the Peace River, a vital source of Florida’s drinking water; it says the U.S. Army Corps of Engineers gave approval for the expansion without first conducting a full environmental audit. The case is unresolved to date.

As for the impending shortages of phosphate, will technological advances and market forces solve the problem? We certainly waste a lot of this most valuable resource. Globally, we allow some 37 million tons of phosphorus to spill into the environment each year. It mostly flows down sewers and agricultural drains into rivers and lakes, where it feeds the growth of toxic cyanobacteria and consumes oxygen, creating eutrophication and “dead zones.”

Ah, eutrophication.  Now we’re looking at water quality.  As a matter of fact, these tremendous phosphate mines in Florida sit at the western edge of the Everglades, consuming huge quantities of land and wetland:


The movie above ends with the plea “Please stop phosphate mining.”  It’s not that simple.  Our entire agricultural model is built upon the availability of phosphorous inputs, and there is no engineered replacement for mined phosphorous (unlike nitrogen, which can be produced from petroleum).  The proposal of another anti-mining advocate is not much better:

Fortunately, the solution is easy. We did it for our first 100,000 years, and we’re the only creatures not currently doing it. The answer is eat, poo, and die in one place.

That doesn’t mean we all have to be farmers, but it does mean we need to be localvores and get over being sqweamish about the fact that we’re animals that are part of the web of life.

Plant food in your yard. Buy the food you don’t grow from local farmers. Insist on pasture raised meat. Compost every organic material you can find. Crap in a bucket. When it’s time to die, have yourself planted in the ground without preservatives so that a tree can build itself out of the molecules you’ve been using.

It’s just not practical for going on 7 billion people to “eat, poo, and die in one place” anymore.  The phosphorous that contributes to poor water quality comes not just directly from mining (permitted in Florida by the Army Corps, which is also responsible for the restoration of the nearby Everglades, which suffers from eutrophication) but from farm runoff all over the world–and we need those farms.  Their productivity would drop dramatically without added phosphorous.

What to do?  It’s too hard to say.  As a finite resource we may be approaching “peak phosphate,” and as we are currently seeing with concerns about “peak oil,” it is very hard to make a global switch in fuels or raw materials used at such a large scale.  Just as with oil, however, we will need to find technological, economic, and behavioral ways to wean ourselves off of phosphate before price and scarcity make it nigh impossible to find.


Thanks to Gabriel Mejias for a tip about the e360 article!

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