As we evaluate geoengineering proposals, we’re faced with a choice of measures of value. Society’s value tranacts for currency, and can be measured in money. Life’s value moves as energy, and can be measured in the joules of sunlight used to create life’s goods and services. Comparative economic analyses can reveal money measures of multiple projects’ costs and benefits; projects’ affordability to society. Similarly, environmental accounting can compare projects’ costs and benefits in the currency of life; projects’ affordability to earth’s life.
Perhaps the first person to formally face this class of decision in a measured way; to face deciding which, of a number of proposals, imposes the least cost or reaps the most benefits for a region’s life, was Dr. H. T. Odum, professor of ecological engineering at the University of Florida,. As we are, perhaps unknowingly, following in his footsteps as we compare geoengineering proposals, let’s understand and consider the methods he developed, and compare them to other options. To compare ecological engineering proposals, Professor H. T. Odum developed environmental accounting, and wrote the book ‘Environmental Accounting: Emergy and Environmental Decision Making’. What’s ‘emergy’? The emergy (with an ‘m’) of a good or service is the amount of energy it took to create that good or service, given the conversion efficiencies involved. Usually sunlight energy is the energy referred to. 1 <#sdfootnote1sym> So, if wheat converts 3% of incident sunlight into biomass, which is 1/3rd harvested grain, the conversion efficiency is 1%, and the emergy of a joule of wheat grain produced is 100 joules of the original sunlight energy it took to create that wheat. Why bother learning this unusual system of accounting? What value does environmental accounting offer the decision maker? Given that we are at, or over, earth’s environmental limits, the cost (and benefit) of geoengineering choices, measured regarding a particular limit, relates directly to the decision being made, just as financial costs and benefits help guide decisions constrained by money. No measure is perfect – just as financial planners balance risk and reward, environmental planners have multiple criteria to balance. Environmental accounting comparisons with emergy offers unique perspective on geoengineering policy decisions. An international society advances emergy research: isaer.org. Also available is this introduction to emergy analysis: http://www.emergysociety.com/emergy-basics/ Brian Cady 1 <#sdfootnote1anc>(when this is so, the units are solar emjoules - the ‘em’ can be thought of as standing for ‘embedded energy’. Solar emjoules are abbreviated as ‘semj’). -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
