Thanatia and the Crepuscular Earth Model - Thanatia: The Destiny of the Earth's Mineral Resources - page 296

planetary albedo. The MEP hypothesis also provides a framework to understand
why photosynthetic life would be a highly probable emergent characteristic of the
Earth as a system and why the diversity of life is an important feature supporting
its function. A biotic Earth at a state of MEP may well lead to near-homeostatic
behaviour over long time scales, as also stated in the Gaia hypothesis”.
Yet it is Medea that reflects the Second Law more extensively 6 . As one should
expect from the Second Law, any system with specified constraints evolves until
it reaches equilibrium with its surroundings, extracting and destroying all exergy
wherever it is found. Indeed if a natural species is a thermodynamic system, it
will reproduce to such an extent that it will end up exhausting the capacity of its
environment to sustain it. And in this sense, the philosophy behind Medea is closer
to that of Thanatia.
The most distinguishing feature of Thanatia compared to the other two is that
whilst they hypothesise the systemic behaviour of a living Earth, Thanatia repre-
sents its death, as a consequence of human action. Rather than the death of Man
through sudden planetary perturbations, it represents the concept of death through
the exhaustion of planetary resources. The reasons behind how Earth arrived at
its present condition are not important, nor particularly relevant. Instead the core
issue centres around the defining of those properties responsible for its commercial
end. Neither Gaia nor Medea specifies these properties, rendering them incapable of
providing any sort of reference for exergy calculations. Hence why Thanatia should
be the reference for the assessment of the loss of mineral endowment.
It is not merely good enough to stay within the philosophical realm, if one is
to truly evaluate the loss of mineral endowment on Earth. Philosophy must be
accompanied by the quantitative and specific composition and concentration of the
Earth's layers with which Man interacts, namely the atmosphere, hydrosphere and
upper continental crust. This is done via the Crepuscular Earth Model as shown in
the next section.
10.3 The Crepuscular Earth Model
In the next sections, the models of the so-called crepuscular atmosphere, hydro-
sphere and upper crust of Thanatia are described. The information provided stems
from the following sources: Valero D. et al. (2010a); Valero et al. (2011).
10.3.1 The crepuscular atmosphere
The crepuscular atmosphere of Thanatia is influenced predominately by the in-
creased concentration of CO 2 due to the complete burning of fossil fuels. A rea-
6 Unfortunately, the Medea theory is too young to find many scientific supporters outside the
paleobiologists circle with little in the way of conferences and studies to corroborate the hypothesis
from other fields like Thermodynamics or environmental sciences.