Epilogue - Thanatia: The Destiny of the Earth's Mineral Resources - page 496

17.2 Thermodynamics and the global view of resources
Thermodynamics unifies concepts. Whilst a deep understanding of this science is
not easy and its application in many cases used only superficially, this branch is a
founding one, whose messages are both well placed and poignant for those wishing to
investigate and push for sustainability. The First Law provides the definition for the
metrics of energy and the basis of material and energy balances. The Second Law is
often used in a metaphorical way. At this point, the analyst abandons the Thermo-
dynamics that he or she considers an aloof scientific instrument and moves towards
those ad-hoc indicators which are more closely related to the spatial-temporal reality
in which we all live. With such indicators one can construct mathematical forecast
models, input-output analysis, LCAs and various other programmes with which to
simulate and analyse the behaviour of various phenomena, including populations,
ecosystems and the financial markets.
However, as the reader could appreciate throughout the topic, the Second Law
plays more than a metaphorical role in the analysis of the evolution and consump-
tion of the planet's natural resources, particularly the abiotic ones, which up until
recently had nowhere near enough been comprehensively examined.
In the construction of a model with which to evaluate the mineral endowment
on Earth the topic has shown that:
Exergy is a universal measure for resource accounting.
Abiotic resources are not well defined thermodynamic systems.
Thanatia is a coherent baseline for mineral exergy calculations.
Exergy costs inform as to the physical irreversibility of production processes.
Cradle-to-grave technologies constitute only half of a material cycle.
Depletion should be measured on a grave-to-cradle basis through exergy re-
placement costs.
The thermodynamic rarity of minerals indicate the hidden and real costs asso-
ciated with production.
The concept of replacement cost apprehends both ideas: conservation and tech-
nological improvements.
The exergy replacement cost of minerals could well become an environmental
indicator.
Such findings are briefly summarised in the following sections.
17.2.1 Exergy is a universal measure for resource accounting
All natural resources are interconnected and this fact is becoming steadily more
evident, as the world looks at its problems through an increasingly global and inter-
temporal magnifying glass. Sustainability provides the overriding conceptual bridge
with which to treat all these problems: there is only one Planet Earth and all must