Geology Reference
In-Depth Information
scale would require huge quantities of energy, meaning that it is nothing more
than theoretically possible to reconvert disperse and chemically degraded minerals
into new mines. Therefore, absolutely replacing elements globally is really a non-
starter
2
. Full stop. Then the only reasonable alternative is pushing for recycling or
continuously scouring the globe for concentrated minerals. These can be broadly
classified into reserves and resources on the basis of their geological certainty and the
ability to exploit them based on the current technological and economic conditions.
Focusing on reserves, they diminish upon exploitation and grow upon exploration.
They vary but can be accounted for. Mineral resources meanwhile, whilst fixed,
are di
cult to evaluate and probably unaccountable. This incertitude makes it
di
cult to ascertain the extent of a potential geologically based supply issue. The
application of exergy can however shed some light by quantifying the tonnage and
grade of geologically known deposits. For their quantification, one has to do nothing
more than obtain annual extraction, mineral composition and concentration data
3
and then calculate the corresponding exergies. These show that independently of
reserves, resources can only ever diminish.
Commercial availability presents a different reality. It can increase for various
reasons, not only due to further extraction. It is also subject to recycling, substitu-
tion techniques and regulation and is a non-linear function of all the externalities
that govern markets. Markets are only interested in the price of raw materials and
they tend to externalise all possible costs. Amongst others, the price of raw materi-
als is a function of the effort and time spent to obtain them and the value (use) one
gives to them. The market almost intuitively raises its prices in response to scarcity.
Such scarcity does not have to be geological in nature. In fact it could have more
to do with circumstances or reflect unrealistic expectations. In this way, whilst ore
grades have continued to decrease, the price of raw materials since 1980 dropped
only to shoot up again in 2002, as occurred in the 1970-80 oil crisis (Kooroshy et al.,
2009). That said, markets are not isolated from geological aspects. Should a new
mine, for example, be located in a remote or extreme place such as deep beneath
the Earth's crust or in the greater depths of the ocean, the price of the mined
material will be high. On the contrary innovations in recycling, substitution and
miniaturisation will tend to lower it. These two increasingly overlap as extraction
velocity speeds up.
2
This does not contradict the idea of using replacement costs as an accounting method in order
to give a value to scarcity.
3
In the same way, one can measure the environmental impact generated by mineral exploitation,
in terms of the amount of rock removed, GHG emissions, water used, land occupied, ecosystems
destroyed and number of people displaced, etc.
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