Monday, August 14, 2023

Worse than climate change, and faster

 kw: book reviews, nonfiction, science, mining, phosphorus

During my grade school years we lived in Salt Lake City, Utah. A few times we visited the Bingham Canyon Copper Mine (AKA the Kennecott Mine), an amazing spectacle. The open pit mine is even larger now than it was then, with an area of about 30 square km, in a ragged oval 9x6 km.

The open pit mine called Phosboucraa, in Western Sahara, about half of which is shown here, is about twice the total size of Kennecott, being 22 km long and mostly between 2 and 3 km wide. The Moroccan company that operates this mine and several others, OCP Group S.A., controls 70% of known world reserves of phosphate rock. However, they're strategically delivering only about 14% of the total ongoing supply, since many other countries, including the U.S., have phosphate mining. Given time, the reserves in Western Sahara will become a virtual monopoly. Let that sink in. Think about that the next time you get some "superphosphate" or "triple phosphate" fertilizer for your garden.

The next image shows the location of the mine in Western Sahara, whose northern border with Morocco is shown dashed, because Morocco claims it, and controls the mining operations. The king of Morocco controls the mining companies (not just OCP), and therefore, more than 80% of the world's phosphate rock.

A discussion of this political and economic quagmire comes midway in the book The Devil's Element: Phosphorus and a World Out of Balance by Dan Egan. He begins with a bit of history of this element that catches fire if it gets to the temperature of bath water, that holds onto oxygen so strongly it takes four O= ions to balance it…and it takes temperatures high enough to nearly melt iron to reduce the oxide to elemental phosphorus.

Before the discussion of the western African mines, we learn of older mining areas such as phosphate-rich oceanic islands and even older "bone beds" in Florida. Some of those are already played out, others will be exhausted soon enough.

What are good sources of phosphorus? Dead things. Phosphorus natively was widely but thinly spread in nature, but is concentrated by living things. All living tissues contain phosphorus. That's you, for example. Mammal meat (muscle) contains from 1/4% to 1/2% phosphorus, and P-rich vegetables such as broccoli contain about 1/16%, mostly in their DNA (carrots come in at 1/30%) and in the ATP/ADP energy-producing system. But our bones have lots more: total phosphorus content of a human body is more than 1% because the minerals in our bones are 18% phosphorus. So old bone beds found worldwide are the sites of many phosphorus mines.

The author shows how phosphorus use developed, not only for fertilizers but also for cleansers (now mostly banned) and, in wartime, for incendiary bombs. Ever heard of eutrophication? It's a fancy word for "green stuff in the water that makes it stink with poisonous fumes." The "green stuff" is mainly cyanobacteria, which used to be called "blue-green algae" but are actually bacteria. I'll call them CB. They are the main source of the stink that comes up a drain if the trap runs dry in an unused sink or shower. Fifty-plus years ago, laundry detergents were the main cause of "algae blooms" (really CB blooms) that turned water green, made it look like overripe guacamole, and it could kill you if you fell in. The Clean Water act led to banning phosphorus in the laundry, but agricultural use was exempted from regulation. Now farms use many times more than in the past, and the runoff is causing even greater problems. 

Many lakes, including Lake Erie, were dying when I lived in Ohio, but were revived when the P runoff was stopped. Now they are in even worse shape. So are parts of the Gulf of Mexico, because the freshwater-plus-pollutants-plus-CB from the Mississippi River pushes out over the salt water of the Gulf, where the CB blooms and makes the beaches in three states unswimmable.

It doesn't have to be that way. In one analysis reported in the book, half of the P fertilizer spread on farm fields runs off before the crop grows, and another nearly 1/4 runs off during the growing season, leaving less than 30% to be taken up into plants. Tilling the post-harvest plant waste back into the soil will at least reclaim that portion. In many cases, that would be enough to bring in a good harvest the following year without adding any new fertilizer. But most farmers are creatures of habit.

There are practices that reduce, and can nearly eliminate, fertilizer runoff. Can long-standing national habits be changed fast enough? Two forces militate against it. One is that tradition dies hard; it's not only in the "Old time religion" that "good enough for Grandpa is good enough for me" holds sway. The other is the mining lobby, that doesn't want demand to be reduced because they are minting billions. If agricultural phosphorus (and nitrogen and potassium, for that matter) were reduced to less than 1/3, multitudes of mining and fertilizer manufacturing workers would need to work elsewhere. It's a big disruption.

Disruption is bound to happen anyway. At the rate of current use, peak production is soon to occur, within a decade or two. Reserves might last for 20-40 years at that point, but they could last centuries if all the world adopted more effective fertilization practices. Recycling food wastes could begin to restore the virtuous cycle that existed before fertilizer-based farming developed. Also, a wholly different style of sewage treatment could reduce the need for mined phosphorus even more (more miners out of work). But if the rocks are all used up, it'll have to be done, or starvation will result. We can't support 8 (or 9) billion humans without fertilizer-based farming…not yet, anyway. But the time will come, probably in the lifetime of people just a little younger than I am, when it must be done, or the population will be reduced by famine (and food riots) everywhere.

That's all likely to happen long before climate change drives everyone north to Canada and Siberia, or south to the southern Kalahari (which could be lots wetter soon) and the southern Pampas of Argentina. Get this book and consider carefully the author's revelations to us.

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