The science and statistics behind the phosphorus shortage.
- By James Elser<p> James Elser is Regents' professor of Ecology in the School of Life Sciences at Arizona State University and co-organizer of ASU's Sustainable Phosphorus Initiative. Stuart White is director of the Institute for Sustainable Futures at the University of Technology, Sydney, Australia, and co-organizer of the Global Phosphorus Research Initiative. </p> , Stuart White
Biogeochemistry: The scientific field that studies the distribution and cycling of chemical elements (such as carbon, nitrogen, and phosphorus as well as iron and other metals) between living and non-living forms in the biosphere.
Phosphorus: The 15th chemical element in the classic Periodic Table. As a chemical element, it cannot be created or destroyed (except in exotic nuclear reactions long completed in the evolving universe). Its unique chemical properties, compared to other elements, give it an especially important role in biology.
Phosphate: The chemical form in which elemental phosphorus is most commonly found. In phosphate, each phosphorus atom is bonded to four oxygen atoms. Phosphate is present at relatively high concentrations in “phosphate rock”, the geological deposits that are mined in fertilizer production.
Nucleic acids: The molecules of genetic information storage (DNA) and processing (RNA). Essential to every living thing, nucleic acids have phosphorus as a key ingredient and indeed phosphorus contributes ~9% of the total mass of a nucleic acid. In turn, in a rapidly growing organism 15-20% of its total mass is contributed by its nucleic acids, especially its RNA. Thus, high yield crop varieties often have high phosphorus requirements.
Apatite: A calcium-phosphate mineral. Apatite is the primary form in which phosphorus is found in geological deposits. Apatite is also the chemical form of P in bones. Indeed, phosphorus represents 12% of the mass of skeletal bone tissue and bones make up ~10-15% of the (dry) mass of a large vertebrate animal, such as a human or a cow.
Haber-Bosch reaction: Energy-intensive industrial process that converts abundant N2 gas in the atmosphere to available chemical forms (ammonia). This process was invented by German and French chemical engineers in 1909 but not put into widespread use for fertilizer production until after World War II. It currently provides nearly all of the world’s nitrogen fertilizer and accounts for ~3-4% of the world’s annual natural gas consumption.
Eutrophication: Increases in blooms of algae and other microorganisms due to excessive inputs of limiting nutrients such as nitrogen and phosphorus. When such blooms crash, subsequent decomposition consumes oxygen and contributes to the growing phenomenon of coastal “dead zones.”