The population of the world depends on having enough phosphorus. Unless we recycle it there will be food price inflation, eventually food shortages and probably famine.

What is Phosphorus: Phosphorus is a natural resource used as a fertiliser in the production of food.  Almost all phosphorus rock is mined in countries outside of Europe, making the EU potentially vulnerable to a future phosphorous and therefore a food shortage.


What is the phosphorus problem?: Phosphorus is key element in fertilizer for the production of food crops. As the population of the world increases, the irreplaceable natural resource is being used increasingly fast. Eventually when this resource becomes scarce, food supplies will not meet world demand, food prices will increase and famine will eventually follow. To avoid this, action must be taken to reduce the wasting of nutrients in waste water and instead to recycle phosphorus resource.

What Irish families can do: Currently phosphorus from a single rural house is not being treated in a sustainable way. At present practically all domestic waste water ends up leaving the house in one single pipe. It passes through the septic tank and the phosphorus and nitrogen is percolated into the soil. We are land filling a finite resource where we should instead be recycling it. We must move away from a linear system of waste water disposal. It is in contradiction to the new European Goals of creating a circular economy, particularly for finite resources such as phosphorus.

To create a circular economy for phosphorus we must insure that it returns into the human food chain. When people consume food that contains phosphorus is will then be passed out in human waste. To tackle this domestic waste water should be separated into three – similar to the 3 bin systems that are now being promoted for solid domestic waste.  Household waste water should therefore be split into toilet solids, urine and grey water, all to be separately managed, allowing phosphorus and nitrogen to be extracted and reused again.

The situation in Ireland

To date here in Ireland phosphorus rock depletion is not a discussed issue in Dáil Éireann or in the public media. This is worrying. To avoid food price inflation and future food scarcity we need to begin a national debate on the new methods that must be implemented to manage and recycle phosphorus more sustainably.

  • Without phosphorus we will be unable to produce fertilizer to grow enough food to feed the already excessive human population in the world.
  • Unlike fossil fuels, for example, that can be replaced by renewable energy; phosphorus cannot be replaced or substituted by any other substance or element.
  • It’s now beyond doubt that the presently known phosphorus rock reserves are limited and finite. Eventually the declining phosphorus mineral resource will become too expensive or too difficult to extract. This is happening with a continuous growth of demand and a growing world population.
  • At present we in Ireland are slow in taking action to address future problems. As the mined phosphorus output declines world wide it will lead eventually to this finite resource becoming depleted. Without phosphorus recycling the continuing growth of large scale industrial and commercial growing of food crops will stop and then steadily start to reduce.
  • We in Ireland therefore should not leave it to the last minute to address this future shortage problem. Because of the present enormous world population we cannot return to the days of relying on animal manures alone to provide fertility for our farming.

Chinese and USA resources

The steepest rise in the cost of phosphorus will most likely happen when depletion of this resource happens in the USA and China. In these two countries the resource is projected to be gone over the next 30 years or so. Indeed these two countries may choose to raise the price for this finite resource before their own national resource is eventually depleted. It would likely become a sellers market.

Opportunities to recycling phosphorus

Domestic house septic tanks are wasteful of nitrogen and phosphorus. Even with frequent emptying of sludge the liquid that enters the percolation pipe contain the largest quantity of Phosphorus. Like the old methods of land filling for solid waste – septic tanks are therefore also “land filling” the finite resource of phosphorus into the ground that thereafter cannot be easily recycled or reused to grow food or crops.

Since the very small volume of human excrement contains about 80% of the nitrogen and phosphorus from domestic waste water it should be easy to keep them separate from the much larger volume of grey water and kitchen waste water. recommends to you is that the domestic waste water should be split in three – similar to the 3 bin systems that are now being promoted for solid waste. For waste water it should be split into toilet solids, urine and grey water, all to be separately managed. This will allow phosphorus to be recovered and will ensure Europe is more resilient in the future when the phosphorus shortage begins to take hold.

Further reading

“Phosphorus is essential for worldwide food security” European Phosphorus platform

Search the Internet: The Story of Phosphorus: 7 reasons why we need to transform phosphorus use in the global food system