Monday, March 7, 2011

"Life's Bottleneck," part 2

The main goal of Isaac Asimov's essay "Life's Bottleneck" is to highlight the important of phosphorous.

"Phosphorous has the highest concentration factor; it is the first element to be used up. Life can multiply until all the phosphorous is gone and then there is an inexorable halt which nothing can prevent."

He continues: "The loss of phosphorous, since that is life's bottleneck, is most serious, and it is estimated that 3,5000,00 tons of phosphorous are washed from the land into the sea by the rivers each year. Since phosphorous makes up roughly one percent of living matter, that means that the potential maximum amount of land-based protoplasm decreases each year by roughly 350,000,000 tons."

He ends this essay, written in 1959 - 52 years ago, in this way:

"Naturally, I am not suggesting that we abandon plumbing and sewers. I am used to sanitation myself aand have no real affection for things like typhoid fever and cholera which go along with lack of it.

I am suggesting, though, that while we try to cope with the inevitable disappearance of coal, oil, wood, space between people, and other things that are vanishing as population and per capita power requirements mount recklessly each year, we had better add the problem of disappearing phosphorous to the list, and do what we can to encourage sewage disposal units which process it as fertilizer rather than dump it as waste - or to mine the ocean floor.

We may be able to substitute nuclear power for coal power, and plastics for wood, and yeast for meat, and friendliness for isolation - but for phosphorous there is neither substitution nor replacement."

Okay, let's fast forward 52 years. What's the phosphorous situation:

Scientific American ran an article on June 3, 2009:
Phosphorus Famine: The Threat to Our Food Supply
As complex as the chemistry of life may be, the conditions for the vigorous growth of plants often boil down to three numbers, say, 19-12-5. Those are the percentages of nitrogen, phosphorus and potassium, prominently displayed on every package of fertilizer. In the 20th century the three nutrients enabled agriculture to increase its productivity and the world’s population to grow more than sixfold. But what is their source? We obtain nitrogen from the air, but we must mine phosphorus and potassium. The world has enough potassium to last several centuries. But phosphorus is a different story. Readily available global supplies may start running out by the end of this century. By then our population may have reached a peak that some say is beyond what the planet can sustainably feed.

Moreover, trouble may surface much sooner. As last year’s oil price swings have shown, markets can tighten long before a given resource is anywhere near its end. And reserves of phosphorus are even less evenly distributed than oil’s, raising additional supply concerns. The U.S. is the world’s second-largest producer of phosphorus (after China), at 19 percent of the total, but 65 percent of that amount comes from a single source: pit mines near Tampa, Fla., which may not last more than a few decades. Meanwhile nearly 40 percent of global reserves are controlled by a single country, Morocco, sometimes referred to as the “Saudi Arabia of phosphorus.” Although Morocco is a stable, friendly nation, the imbalance makes phosphorus a geostrategic ticking time bomb.
[The rest of the article can only be read online by subscribers...]
In Brief
Mining phosphorus for fertilizer is consuming the mineral faster than geologic cycles can replenish it. The U.S. may runout of its accessible domestic sources in a few decades, and few other countries have substantial reserves, which could also be depleted in about a century.
Excess phosphorus in waterways helps to feed algal blooms, which starve fish of oxygen, creating “dead zones.”
Reducing soil erosion and recycling phosphorus from farm and human waste could help make food production sustainable and prevent algal blooms.

So after 50 years, we are still a few decades away from running out of phosphorous, but the environmental impact of excess phosphorous in water zones have been wreaking havoc for decades, and continue to do so.
* Seaborn: Oceanography Blog
* Star Trek Report: Space Sciences
* Volcano Seven: Treasure and Treasure Hunters
* Rush Limbaugh Report

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