Peak phosphorous is not happening

Phosphorous is an essential ingredient of fertilizer and is a basic building block of all life. Without phosphorous, it’s impossible to grow crops or plants of any kind. Phosphorous has no substitutes, because phosphorous specifically is required for plant DNA, and it would take hundreds of millions of years (if ever) for life to evolve to use something else.

At present, the world uses about 140 million tonnes of rock phosphate, for fertilizer production. The total world reserve of rock phosphate is 8,000 MT. At current rates of usage, we will reach “peak phosphorous” in 2033 according to this Hubbert analysis. After which, extraction of phosphorous would gradually decline, and so would fertilizer production and food production, if that analysis were correct.

This point is repeatedly raised within “peak oil” type doomsday circles, and is provided as another reason for the imminent collapse of civilization. Bear in mind that this point is raised by precisely the people who have made a very long string of badly failed doomsday predictions. Obviously, they could be right this time, however their opinions on this matter should not be confused with scientific consensus.

In fact, the doomsday authors are entirely wrong about phosphorous. As usual, the doomsday group’s point is totally wrong and is based upon a series of misunderstandings. We do not face declines of phosphorous in the foreseeable future. Quite the opposite, we have vastly more phosphorous available than we could ever use.

In my opinion, the idea of “peak phosphorous” is vastly less serious and more obviously wrong than the theories of peak oil were, and even those were wrong.

Analysis of “Peak Phosphorous” claims.

The doomsday advocates in this case are making a severe error which invalidates their analysis. They are confusing reserves of phosphate rock, with the total amount of phosphorous available in the Earth’s crust. Reserves of phosphate rock refers to the amount of phosphorous which is found in a particular form and has already been discovered. The total amount of phosphorous available, however, is vastly greater than that.

It bears repeating here that published reserve figures of phosphate rock do not represent the total amount of phosphorous available. Instead, reserve figures only represent the very small amount of phosphorous which is found in highly concentrated form and so would be extracted first. Reserve figures of phosphate rock are only a very small fraction of the total phosphorous available.

As with many elements in the Earth’s crust, phosphorous is distributed according to a resource pyramid. There is only very small amount of phosphorous available in a very concentrated form (the “tip of the pyramid”). In more dilute concentrations, there is vastly more phosphorous available. The greater the dilution, the more is available. Published reserve figures refer only to the very tip of the pyramid–the very small amount of resource which is highly concentrated and easily extracted. There is far more resource available in more dilute forms.

Mineral resources are very different from oil or gas. Whereas oil is found in underground reservoirs which are “depleted” at some point, mineral resources are found in gradations, and are available in vastly greater quantities at lower dilutions.

When current reserves are exhausted, prices for phosphorous will rise, and it will become economical to extract phosphorous from more dilute sources. In other words, we will take a step down the “resource pyramid” and start to exploit more dilute sources which are found in far greater amounts. The technology to extract phosphorous from more dilute sources is straightforward and already exists. Thus, the exhaustion of current reserves, does not mean we are out of phosphorous. It means only that we must start extracting phosphorous from more dilute sources.

If we wish to find out how much phosphorous is available to us overall, we must determine how much could ever be extracted. Please note that the total amount which could ever be extracted is completely different and far higher than published reserve figures of phosphate rock.

So how much phosphorous is there?

Phosphorous is a fairly common element. Phosphorous constitutes about 0.1% of the Earth’s crust. It’s the 11th most common element and is far more common than all sources of carbon in the Earth’s crust. This figure was determined by statistical sampling and can be looked up in the wikipedia article about elemental abundance in the Earth’s crust

We can easily calculate the total amount of phosphorous in the Earth’s crust:

1025 g total mass of the Earth’s crust

1019 tonnes total mass of the Earth’s crust (unit conversion)

1016 tonnes of phosphorous (1 part per 1,000, derived from wikipedia article)

1010 tonnes of phosporous in phosphate rock reserves

Thus, we have 10,000,000,000,000,000 TONNES of phosphorous available in the Earth’s crust. That amount is approximately 1 million times higher than published reserve figures of phosphate rock.

Of course, most of the phosphorous in the Earth’s crust will never be extracted. Much of it lies beneath Oceans, or deep underground. However, if we are ultimately able to extract even 0.1% of the total phosphorous in the Earth’s crust then we will have 1,000x more phosphorous available to us than the reserve figures indicate. In which case, phosphorous will not “peak” for centuries or millenia.

Since phosphorous is crucial, it would become far more expensive if it were ever scarce, which would justify extracting it even from very dilute sources. It’s entirely plausible that phosphorous could be extracted from 1% ore concentration, which would provide vastly more than figures of phosphate rock reserves would indicate.

Phosphorous recycling

Even if phosphorous extraction peaked and started declining, it would not be particularly worrying. Although phosphorous is used to grow food, it’s not being “used up” at any rate. Humans excrete all the phosphorous they consume from food, in their feces and urine. The average human excretes about 1kg of phosphorous per year. In other words, phosphorous is not really being used up at any rate, because as much of it exists on Earth after we’ve used it as existed beforehand. If phorphorous became significantly more expensive, then sewage and food scraps would have monetary value and would become additional sources of phosphorous. It would become profitable to “mine” sewage and garbage for phosphorous, and sewage utilities and transh utilities would begin doing just that. In so doing, we would “recycle” the phosphorous we had mined from the ground. If we managed to “recycle” 90% of our phosphorous by using it judiciously and extracting it from sewage and garbage, then the amount we’d need to mine from the ground would obviously decline by 90%, in which case, actual declines in phosphorous available to us would be perhaps 10,000 years away (just eyeball estimating how long a 90% depletion would take on a Hubbert curve with 1,000x more phosphorous than published estimates of phosphate rock reserves). These adjustments and recycling programs would happen automatically, the result of basic market mechanisms, as phosphorous becomes more expensive. It would become profitable to extract phosphorous from sewage and garbage, and so would be done by companies which would never leave any obvious profit opportunities unexploited.

We may never reach peak phosphorous

Even if we have 1,000x more phosphorous available to us, and we also start recycling (“mining sewage”), won’t we reach peak phosphorous eventually? In 10,000 years, perhaps?

Not necessarily. That depends upon demographic trends.

At present, fertility is declining everywhere. In almost all advanced nations, fertility is below replacement rate meaining their populations are shrinking, or would shrink without immigration. Furthermore, there is every reason to believe that fertility rates will also decline below replacement in poorer countries as they develop (in fact, their fertility rates are already declining fairly rapidly). As a result, it’s probable that the human population will start declining absolutely at some point during the next century. As a result, we will probably reach peak phosphorous DEMAND long before we encounter peak production.

If the human population declines below 1 billion people over the next few thousand years, then no phosphorous extraction would be required for agriculture at that point, because phosphorous is recycled in the soil and environment (by natural means) more quickly than would be necessary. In which case, we would never reach peak phosphorous, or at least not in the sense that doomsday believers are claiming. We would reach a peak of phosphorous extraction because of reduced need, not because of any kind of shortage. We may never face a shortage of phosphorous.

Whether we face a shortage of phosphorous in the future depends upon demographic factors over the next few thousand years. It’s impossible to predict. However, there is no inevitable shortage of phosphorous, over any time scale, just from current trends.

If current trends reverse themselves, and the human population starts growing again and keeps growing, then we will face shortages of something at some point. The growth of the human population would eventually be limited by some factor. However, it is not just inevitable and is not imminent.

Civilization is definitely not collapsing because of peak phosphorous

Some of the doomsday believers have claimed that peak phosphorous will cause the collapse of industrial civilization. As phosphorous declines, industrial agriculture will decline, and with it, industrial civilization. This concern was raised here and here , and has been raised repeatedly over the years within doomsday prepper groups. The theory that peak phosphorous will cause the collapse of civilization, is entirely wrong and is based upon severe misconceptions of how the world economy works. Even if we assume that phosphorous extraction will soon start declining (which it obviously won’t; see above) it still would pose no risk of the collapse of civilization. Instead, it would cause FAMINE in the poorest countries of the world, probably those of sub-saharan Africa, because citizens of the first world can easily outbid them for gradually declining amounts of fertilizer.

Of course, every effort must be made to prevent famine in Africa. However, it’s counter-productive to engage in doomsday prepper activities like hoarding ammunition, relocating to rural locations, or growing their own food, because doing so is preparing for an event (collapse of civilization) which is not happening. It would do nothing to prevent famine in Africa to engage in activities like that. Thus, doomsday prepping is just counter-productive in this case and would do nothing to ameliorate the effects of phosphorous shortages even if they occurred.

Conclusion

The whole notion of the collapse of civilization because of “peak phosphorous” is just totally wrong, for many different reasons. As follows:

Doomsday authors are confusing reserves of phosphate rock, with the total amount of phosphorous available. They are under-stating the total amount of phosphorous available to us by at least a factor of 1,000. Doomsday authors are failing to account for obvious recycling opportunities which would become profitable and would happen automatically as a result of basic market mechanisms. Doomsday authors are conflating a fertilizer shortage with the collapse of civilization, when the two have nothing to do with each other. A shortage of fertilizer would cause starvation in sub-saharan Africa, but not the collapse of industrial civilization. Any such problems would be better addressed by birth control programs in Africa, and not doomsday prepping. Doomsday authors are ignoring demographic trends which will reduce the demand for phosphorous long before any shortages occur.

Each one of the above errors is fatal to the doomsday thesis. Thus, the doomsday idea of collapse because of “peak phosphorous”, is refuted four times over.

If the above errors are avoided, then it’s not clear that phosphorous shortages will ever occur, over any time scale. Whether there will be phosphorous shortages ever, is something which can’t be predicted at present. However, there are definitely no imminent shortages of phosphorous, and there won’t be shortages for a very long time.

In closing, I should point out that these doomsday theories are NOT SERIOUS SCIENTIFIC THEORIES. These doomsday theories and speculations are filled with so many severe errors that their conclusions are just not supported.