28 January 2014

The world was given a shock when global phosphorus prices were raised by 800% in 2008. At a stroke, it became clear how dependent we are on phosphorus for our food supply. Phosphorus is an ingredient in artificial fertilizers and is indispensable in modern farming.

A few years later, after her work as a graduate student/researcher at Water and Environmental Studies, Dana Cordell coined the term “peak phosphorus”, analogous with “peak oil”. She and her co-authors predicted a future shortage of phosphorus that the world is badly or not at all prepared for. Their article, “The story of phosphorus: Global food security and food for thought” has become the most downloaded and cited article in the history of the journal Global Environmental Change.

In a new article, LiU researchers Tina-Simone Neset and Ms Cordell have now put forward a framework for qualitatively analysing our vulnerability to a future shortage of phosphorus.

“The question has so far been discussed mostly from a geophysical perspective,” says Ms Neset. “How large are the physical resources and how long will they last? But the issue is much more complicated than that.”

Extreme geographic concentration

Especially geopolitically. The geographic concentration of phosphorus is extreme; six countries control more than 90% of the world’s resources: Morocco, China, Algeria, Syria, Jordan and South Africa. In the case of Morocco, one source of phosphate ore is Western Sahara, which was occupied by Morocco in contravention of a UN decree. And in several of the other countries, the political situation is unsure to say the least.

On the other hand, a number of large countries and regions, such as India, the European Union and Brazil are almost completely dependent on imported phosphorus for their agriculture.

“We wanted to test the concept of vulnerability developed within resource and climate research, and in this field too. There are many factors besides the pure physical global supply that decide how vulnerable a population is in the face of a future shortage of phosphorus,” says Ms Neset.

In the analysis framework the researchers are now proposing there are 26 indicators that may be tested on different levels: global, regional, national or local. Examples of indicators are international trade regulations, energy prices, eating customs, population, dependence on imports, food security, owners and producers of phosphate ore, infrastructure (transport), soil fertility, and distribution of income.

The researchers propose that the analysis should first be carried out at the national level, where the decision makers are in the best position to influence factors such as agricultural policy, the financial situation of the farmers, infrastructure and recycling.

No possible substitute

Because even if the phosphate ores are a finite resource where (in contrast to oil) there is no possible substitute, phosphorus may be recycled in a loose form. It is present, for example, in the urine and faeces of both humans and animals. By making better use of this waste it would be possible to reduce dependence on imported phosphorus, and also reduce the impact on the environment that arises when phosphorus washes out into lakes and oceans, and contributes to eutrophication.

“The decision makers need to become aware of and adopt a stance towards these issues,” says Ms Neset. “How dependent are we on imported phosphorus? What should we do if prices were to rise sharply? Would it be possible to reduce this dependency in some way?”

How long the global reserves of phosphate ores will last is a hot topic of debate. A few years ago the figure for known reserves of phosphate ore was scaled up from 16,000 to 67,000 megatons. But, says Ms Neset, the estimates are uncertain. And even in the most optimistic prognoses, the phosphate ores will have run out within a couple of hundred years.

The article by Ms Cordell and Ms Neset was published in the journal Global Environmental Change with the title “Phosphorus vulnerability: A qualitative framework for assessing the vulnerability of national and regional food systems to the multi-dimensional stressors of phosphorus scarcity.”