Phosphorus is now mined at a rate of about 17.5 metric tonnes per year, with about 80% being applied to crops. Since the supply of minable phosphorus ore will last only for a few more decades, technologies will need to be developed to recover most of the P being lost to runoff, animal waste, and human waste. Likewise, the so-called “green minor metals” have finite supplies and will need to be recycled. The most critical are tellurium, indium, and gallium, which are key to photovoltaic technology.
• What resources can be produced renewably or recovered by developing intense technologies that can be applied on a massive scale?
• What resource do we need to produce/recovery this way?
• What is the likelihood that we can develop intense, massive technology to do it?
• What are the impacts that need to be evaluated before we implement the technologies?
• Economic—how much will it cost to develop, implement, and operate? How can we afford to make the investments?
• Ecological—how will ecosystems be altered by massive implementation of renewable technologies that necessarily take up a large surface area?
• Environmental/climate—how will the massive implementation of renewable technologies alter climate or other environmental conditions? What other environmental conditions?
• Social—how will the organization of societies be altered by the massive implementation of renewable production/recovery technologies?
• Social/Economic—who will benefit or be hurt by the shift to renewable sources on a massive level?
• What are the foreseeable successes?
• Are catastrophic failures foreseeable?
Buchert M, Schüler D, and Bleher D. Critical metals for future sustainable technologies and their recylcling potential. United Nations Environment Programme & United Nations University, 2009.
Carpenter SR and Bennett EM. Reconsideration of the planetary boundary for phosphorus. Environ Res Lett 2011;6:1-120.
Elser J and White S. Peak phosphorus. Foreign Policy 2010.
Rittmann BE. Opportunities for renewable bioenergy using microorganisms. Biotechnol Bioeng 2008;100:203-212. [Abstract available.]