The increasing use of phosphorus-based fertilizers will eventually lead to the “peak phosphorus,” where not enough quantity of this element will be available to match the demand.
What’s happening to all the phosphorus, and what will happen when supply fails to meet our demand?
What is Phosphorus?
Phosphorus (P) is an element which is indispensable for all forms of life on Earth – human, animal and vegetable.
P is present in humans and animals in different forms, for instance in bones as calcium phosphate, in DNA, in some lipid molecules (phospholipids), etc.
In plants, phosphorus is an element essential for their nutrition; because of this, almost all fertilizers contain phosphorus.
Phosphorus availability is, therefore, crucial for agriculture and, consequently, food production.
Phosphorus Sources and Production
The main phosphorus sources are phosphate rocks, which are non-renewable. The majority of the phosphate reserves – about 75 % – are located in Morocco, which is the premier world phosphorus producer. Other producer countries are China, US, Russia and Canada.
Phosphorus production increased dramatically in recent decades; literature data report that world production went from 45.5 metric tons (MT) in 1961 to 198.0 MT in 2011.
Such a rise is due to several factors; the increase in the world population, and the consequent higher food production, is surely one of the reasons for a higher demand phosphorus. More than 80% of phosphorus is used for fertilizer production.
Both world population and food demand will increase in the upcoming years; this will mean that phosphorus demand and production will be higher too. The increase in production, however, cannot continue forever, as eventually a maximum value will be reached.
Phosphorus production will not continue to grow due to the limited / decreasing availability of the phosphate rocks from which the elements is extracted.
The maximum value in the phosphorus production is generally referred to as “peak phosphorus.”
Phosphorus Shortage: Consequences
According to some studies, peak phosphorus can have serious consequences for our society. Insufficient fertilizer production can cause an increase in its price which, in turn, will lead to higher food prices. This is likely to affect a great number of people, especially in poorer countries. Eventually, we could experience decreases and shortages in food production.
When Will Peak Phosphorus Happen?
The fact that eventually phosphorus production will decrease is a widely accepted concept. It is not clear, however, when this decrease will take place. In other words, there is no agreement on when the peak phosphorus will happen.
A study published in 2009 estimated that the peak phosphorus should have occurred around the year 2030. In more recent times, however, scientists have questioned the reliability of this first estimate.
More Phosphorus Resources
Since the first studies were published, the estimated reserves of phosphorus minerals increased; this led to the conclusion that the peak will not occur in the immediate future, but later on in time.
According to recent literature data, a more likely date for peak phosphorus is around the year 2070. Other analyses predict an even more distant date; a report published by the Kiel Institute for the World Economy, for instance, states that it is not likely that peak phosphorus will occur within this century.
It has to be highlighted, however, that resource availability is not the only parameter which may affect phosphorus future demand and production; in fact many other issues may determine when we’ll run out of phosphorus.
The growth in food demand, for instance, will depend on the size of the world population, but also on the increase in income of people in developing countries. This second element is more difficult to predict; this causes an uncertainty in the increase in phosphorus production.
Another issue can be how common the use of fertilizers will be in the future. At present small-hold farmers, especially in less developed countries, do not commonly use much fertilizer; in the future this may change. A more extensive use, however, can lead to higher food production; therefore, the overall effect on food availability may be positive.
Careful Use of Elements and Renewable Sources
Although it will not occur in the immediate future, and there’s no massive food shortage likely as a result, it is important to keep in mind that the resources for this element will eventually be exhausted.
Therefore, it is important to implement policies which would lead to a more careful and efficient phosphorus use. We should consider recycling and reusing phosphorus from other sources (i.e. industrial wastes). As well as recycling, another renewable source of phosphorus that could be exploited more in the future is from biogenic origins, such as bird and bat guano (droppings), a resource very rich in phosphorus, that accounts for 2-3% of the total global phosphorus content.
Phosphorus Shortage: Be Concerned
Despite all these uncertainties, a phosphorus shortage is something we should be concerned about. Although the point where we cannot meet demand for this critical element is far in the future, now is a good time to start making changes.
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