I’m a chemist and if you asked me what phosphorus (P) is, I’d say it’s an element of the periodic table with atomic number 15. This means it has 15 protons that forms the nucleus (along with an equal number of neutrons) and 15 electrons that move around the nucleus. But this isn’t my chem 101 exam, so this isn’t the story I want to tell today. In fact, the tale I’d like to talk about is about the possible extinction of P, a story that no one has heard of.
We constantly hear about loss of biodiversity, animals, insects, and plants at risk of extinction because of global warming, greenhouse gas emissions, poaching etc. What about phosphorus? Just because it’s an invisible chemical element, isn’t it worth the media attention? Loss of biodiversity is indeed a serious problem, but the world isn’t only losing flora & fauna. It’s destroying the reserves of chemical elements too and the incoming shortage of phosphorus is the most serious problem everyone should care about.
Nearly 90% of P global demand comes from agriculture and farming. In fact, phosphorus, or better its derivatives called phosphates, are used as crop fertilisers. During the centuries following the industrial revolution, farmers noticed that adding sources of P to crops had a positive impact on harvesting and would increase crop supplies. Countries that could afford it replenished the P in their soils with P-rich guano (seabird and bat excrement accumulated over several millennia). A thriving industry quickly rose to export guano from Peru to Europe and many workers in South America were forced to work in dangerous and life-threatening conditions to satisfy the appetite for P across the Atlantic [1].
The guano deposits were quickly exhausted, and by the beginning of the 20th century, the guano industry collapsed along with the native environment for many birds which was permanently destroyed [2]. Around that time, other solutions were implemented to enrich soil with P, and a common practice was to treat bone meal with sulfuric acid. Alternately, treating phosphorous rocks with acids could produce similar positive effects on crops and increase harvest production. The process of obtaining P from rocks became so widely-spread to the point of being translated into industrial scale and it has been the most used practise since [3].
It is estimated that ~85% of the phosphates produced from phosphorus rocks are used to produce mineral P fertilisers [3, 4]. The world supply of phosphorus rocks relies mainly on 2 or 3 geographic areas, China, the Middle East and North Africa with 70% of those rocks located in Morocco and other sub-Saharan countries. Those are not only limited resources but intensive mining has also a negative impact on the ecosystem and geological properties of sediments. Additionally, a shortage of phosphorous for crop production will increase the gap of existing food inequalities between countries that can offset the potential rising cost of the minerals and those that can’t. With the number of people living on the planet expected to increase, solutions towards rethinking the way we use P seem a urgent necessity.
How long do we still have and what can we do to reverse or mitigate the risk of running out of phosphorus?
There’s no doubt that phosphorus is an element at risk of extinction. Scientists at the Massachusetts Institute of Technology (MIT) created an online platform called “Mission 2016: Strategic Mineral Management” to raise awareness to the problem of depletions of chemical elements and minerals as well as providing evidence-based and informed solutions on mineral management. Due to the urgency of the problem, they dedicated an entire section to P. The authors claim that P reservoirs might run out in approx. 80 years if we keep mining P at its current rate. This period of time can be extended to more than 300 years if action is taken.
Another report on the problematics around P shortage is available to read online, Our Phosphorus Future: toward global P sustainability. The report was supported by a few European scientific agencies & the UN Environment Programme. 100 scientists and industry experts worked on writing the report which started in 2017, went through 3 peer-review rounds and was published in 2021. That seemed perfect timing for its publication as the global pandemic aggravated the issue of food security and highlighted the need for more sustainable practices that respect the environment and the people who populate a certain environment.
Outside reporting facts and evidence on the urgency of the problem, the authors also proposed a few solutions that could be easily implemented to create more sustainable practice around P usage. They recommend the use of alternative source of P other than rocks, implementing new ways of recovery and using recycled P coming from solid or liquid waste. Additionally, there’s a need to optimise/reduce the use of P as fertiliser as well as a nutrient for animal farming. By looking at their recommendations, it is clear that this isn’t up to the individual to put a system in place to extend the lifetime of P.
This can only happen by implementing new legislations around water and waste monitoring for P, putting a cap on how much P can be mined from rocks every year and introducing more stringent laws around the use of fertilisers. We seem to never learn anything from history, and because the reservoirs of P will deplete in 80 years, this can be deemed as another day problem. Guano reserves did run out within 50–60 years since commencing its use for worldwide harvesting. Do we really want the same outcome for phosphorus rocks?
If you’re interested in writing an evidence-based article to raise awareness to environmental problems or ways to reach towards a more sustainable future, please contact me at teresaambrosio.com
References:
[1] The American Historical Review, 2012, 117, 1028–1060
[2] Schnug, E., F. Jacobs, and K. Stöven. 2018. Guano: The White Gold of the Seabirds. In: Mikkola, H., editor, Seabirds. InTech, London, UK. p. 81–100
[3] Chemosphere, 2011, 84, 737–746
[4] Global Environmental Change 2009, 19, 292–305
OFC report can be found by clicking here.
Mission 2016 on P can be found by clicking here
Teresa Ambrosio Consulting 