Peak Phosphorus: Opportunity in the Making
http://www.iisd.org/publications/pub.aspx?pno=1225
The interesting December 2009 report Peak Phosphorus: Opportunity in the Making was published by the Manitoba-based nonprofit International Institute for Sustainable Development (www.iisd.org). It is subtitled “Why the phosphorus challenge presents a new paradigm for food security and water quality in the Lake Winnipeg Basin.” The 18-page report is available for free downloading from the web site above or directly from http://www.iisd.org/pdf/2010/peak_phosphorus.pdf
Peak phosphurus is defined by the authors as “a moment in time when demand for rock phosphate will exceed supply.” The report notes that peak phosphate production was reached in the US in the late 1980s, and that it is possible that peak world extraction could be reached as early as 2030. It also states
that, in recent decades, data show that more phosphate is being extracted than is being discovered.
According to the report:
“The long-term security of our global food and water supplies may be impacted by the mismanagement of our phosphorus nutrient resources. Essential to plant growth and all life, phosphorus is mined from rock phosphate deposits and synthesized into mineral fertilizers destined for agricultural fields. Easily mined rock phosphate reserves are dwindling, and the contraints this could place on fertilizer production pose risks to our long-term ability to feed the planet.”
The authors consider how impending peak phosphorus can actually provide an opportunity for using new approaches to address current environmental problems in Lake Winnipeg’s watershed (the second-largest drainage basin in North America, which includes significant portions of North and Northwest Minnesota as well as portions of three other states and four Canadian provinces).
The report notes how runoff of excess phosphorus from agricultural fields (as well as from urban areas and other sources) is causing serious pollution problems for waters and aquatic ecosystems - because too much phosphorus can lead to rapid algal growth and eutrophication (see http://en.wikipedia.org/wiki/Eutrophication for general information about eutrophication). Lake Winnipeg, the world’s tenth-largest freshwater lake, is actually the most eutrophic large lake in the world according to the report and is experiencing massive algal blooms.
The authors argue that limited supply and a higher price for phosphorus may have a positive side, possibly stimulating more efficient agricultural and other practices that will limit runoff and improve plant uptake of this critical nutrient, as well as leading to greater phosphorus recovery from manure and human and food wastes through advances in wastewater treatment and waste management. Several options for phosphorus reduction and recovery are noted, which include using struvite to precipitate phosphorus in wastewater, using composting toilets, separating and collecting urine through waterless urinals for use in fertilization, reducing food waste, treating sewage sludge for phosphorus recovery, adopting site-specific nutrient management in agriculture, recovering phosphorus from livestock waste, and other actions.
For those interested in learning more about the broader topic of “peak phosphorus”, see also a recent collection of a range of articles on the topic posted at http://www.energybulletin.net/node/52550 (The comprehensive and frequently-updated Energy Bulletin web site www.energybulletin.net is an excellent source for tracking this issue, as well as others related to resource depletion.)