Editing Phosphorus (section)

===Reserves===
[[File:Global phosphate rock production USGS 1994-2022.png|thumb|Annual global phosphate rock production (megatonnes per yr), 1994–2022 (data from US Geological Survey){{r|USGS2023}}]]

Phosphorus comprises about 0.1% by mass of the [[Earth's crust]].{{r|AGU2007}} However, only concentrated forms collectively referred to as [[phosphate rock]] or phosphorite are exploitable, and are not evenly distributed across the Earth.{{r|Greenwood1997}} Unprocessed phosphate rock has a concentration of 1.7–8.7% phosphorus by mass (4–20% phosphorus pentoxide). The world's total commercial phosphate reserves and resources are estimated in amounts of phosphate rock, which in practice includes over 300 ores of different origin, composition, and phosphate content. "Reserves" refers to the amount assumed recoverable at current market prices and "resources" refers to estimated amounts of such a grade or quality that they have reasonable prospects for economic extraction.{{r|Sutton2013|CIM2010}} Mining is currently the only cost-effective method for the production of phosphorus. Hence, a shortage in rock phosphate or significant price increases might negatively affect the world's [[food security]].{{r|Amundson2015}}

[[File:Global distribution of commercial reserves of rock phosphate USGS 2016; GTK 2015.jpg|thumb|upright 1.3|Global distribution of commercial reserves of rock phosphate in 2016]]
The countries estimated to have the biggest phosphate rock commercial reserves (in billion metric tons) are [[Morocco]] (50), [[China]] (3.2), [[Egypt]] (2.8), [[Algeria]] (2.2), [[Syria]] (1.8), [[Brazil]] (1.6), [[Saudi Arabia]] (1.4), [[South Africa]] (1.4), [[Australia]] (1.1), [[United States]] (1.0), and [[Finland]] (1.0).{{r|Ahokas2015|USGS2023|USGS2025}} Estimates for future production vary significantly depending on modelling and assumptions on extractable volumes, but it is inescapable that future production of phosphate rock will be heavily influenced by Morocco in the foreseeable future.{{r|Walan2014}} According to some researchers, Earth's commercial and affordable phosphorus reserves are expected to be depleted in 50–100 years.{{r|Cordell2009}}

In 2023, the [[United States Geological Survey]] (USGS) estimated that economically extractable phosphate rock reserves worldwide are 72 billion tons, while world mining production in 2022 was 220 million tons.{{r|USGS2023}} Assuming zero growth, the reserves would thus last for around 300 years. This broadly confirms a 2010 [[International Fertilizer Development Center]] (IFDC) report that global reserves would last for several hundred years.{{r|IDFC2010|VanKauwenbergh2010}} Phosphorus reserve figures are intensely debated.{{r|Sutton2013|Cordell2009|VanVuuren2010}} Gilbert suggest that there has been little external verification of the estimate.{{r|Gilbert2009}} A 2014 review concluded that the IFDC report "presents an inflated picture of global reserves, in particular those of Morocco, where largely hypothetical and inferred resources have simply been relabeled “reserves".{{r|Edixhoven2014}}