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Emergy baseline for the Earth: A historical review of the science and a new calculation
Citation:
Campbell, Daniel E. Emergy baseline for the Earth: A historical review of the science and a new calculation. ECOLOGICAL MODELLING. Elsevier Science BV, Amsterdam, Netherlands, 339:96-125, (2016).
Impact/Purpose:
This paper may be highly significant for the global community of scientists performing emergy research, if its recommendations are vetted and accepted as the basis for future emergy calculations. In this paper, major conceptual and numerical errors are corrected that were a part of earlier calculations. Calculations are made to check the numbers proposed in this paper and arguments are given to demonstrate the plausibility of these results within the context of the predictions of Energy Systems Theory principles. The stated goal of this paper is, “to provide the community of scientists with a more accurate estimate for the planetary emergy baseline of the Earth. In the process we will demonstrate that the planetary emergy baseline of the Earth is not arbitrary and that the choice of a baseline is a matter that ultimately reflects on the scientific integrity of emergy research, if not the practical outcomes of emergy evaluations. The objectives of this paper are first to demonstrate the need for a new calculation of the planetary baseline for the Earth and second, to carry out that calculation, estimating the value of the baseline from 555,000,000 years BP to the present time…” Thus, the potential impact and significance of this work is high.
Description:
Quantifying the emergy baseline of the Earth is a practical necessity for emergy evaluations, because it serves as a unified basis for determining transformities of the available energy storages and flows of the geobiosphere. The current debate over the value and significance of the planetary baseline has been in progress since 1998, when the author first brought new data on geopotential energy formation in the world oceans to H.T. Odum's attention. In this paper, past studies of the baseline were reviewed and errors in data translation and model formulation were found to be sufficient to justify a new calculation. A fundamental epistemological obstacle to establishing a unified planetary baseline (i.e., the production functions for deep Earth heat and tide as a function of solar radiation are unknown) is overcome by using the transitive property of equalities to estimate equivalences between solar radiation and Earth's deep heat exergy flows (4200 solar equivalent joules per joule, seJ J−1) and between the exergy of solar radiation and the tidal exergy dissipated in the oceans (35,400 seJ J−1). At present, the planetary baseline for the Earth with its ice-covered, polar oceans is approximately 1.16 × 1025 seJ y−1 and the distribution of the emergy or the organizing power of the inputs is: 1/3 solar radiation, 1/3 deep Earth heat and 1/3 tidal geopotential energy. In addition, the planetary baseline has been remarkably stable over the past 555,000,000 y (1.00 × 1025 ± 1.13 × 1024 seJ y−1 or within ±11%). The tidal exergy dissipated in the world oceans over this time varies from 31% to 155% of its present value largely due to the changing efficiency of the Earth as a “machine” for generating tidal exergy. Close correspondence of the value and properties of this new baseline with the principles of Energy Systems Theory indicates that it should be preferred over prior determinations.
