Environmental Engineering Reference
In-Depth Information
400 years of current global NPP. In a fiscal analogy, pre-
industrial societies relied on instantaneous or minimally
delayed and constantly replenished solar income, whereas
modern civilization is withdrawing accumulated solar
capital at rates that will exhaust it in a tiny fraction of the
time needed to create it. Preindustrial societies relied on
constantly renewable energies (on a time scale of many
millennia) and were thus truly sustainable, at least in
theory, because some of their practices caused excessive
deforestation and soil erosion, which reduced or even
prevented regeneration of phytomass energy.
In contrast, modern civilization rests on the indubita-
bly unsustainable harnessing of a unique solar inheritance
that cannot be replenished on a civilizational time scale.
We are living in an energetic interlude because the stores
powering our way of life are finite, and even the best
conversion efficiencies and the utmost conservation mea-
sures cannot extend their life beyond several hundred
years. Yet we will never exhaust all the recoverable
reserves of fossil fuels, the share of overall resources that
can be produced with available techniques at a known
cost. Long before reaching that point we will either go
back to immediate solar flows harnessed in ways vastly
superior to preindustrial practices, or we will put in place
new arrangements dependent on another, more durable
class of stores, such as advanced nuclear options or en-
tirely new, as yet unknown conversions. In any case, this
means that modern economies are, from the fundamen-
tal energetic point of view, unsustainable.
But tapping the available solar capital of amassed fossil
fuels made it possible to temporarily harness sources of
extraordinarily high energy that are also relatively easy
to store and transport. Our ingenuity has been convert-
ing them into a variety of final energies (including ther-
mal, kinetic, chemical, and electric) that can be used
with unprecedented efficiency and flexibility. Both past
achievements and the immediate prospects of modern
civilization are defined by this consumption of fossil fuels.
In this chapter I first describe their attributes and
resources, and then survey the progress of their extrac-
tion, transportation, combustion, and conversion to elec-
tricity. Fossil-fueled civilization as a high-energy system is
the subject of chapter 9.
Although Thomas Gold and some Russian and Ukrai-
nian geologists argued the case for the abiogenic origin
of some hydrocarbons (see section 8.2), most fossil fuels
are clearly organic mineraloids with minor admixtures
of inorganic compounds and alkaline and metallic ele-
ments. Their physical state at ambient temperature
divides them naturally into solids (coals), liquids (crude
oils), and natural gases. Plurals are necessary in order to
convey the considerable heterogeneity of these fossil
fuels. Coal qualities range widely, crude oils are, as far as
heating value is concerned, much more uniform, and the
energy density of natural gases varies within a very nar-
row range. But even fuels with identical energy content
command different prices because of the presence or
absence of undesirable constituents (sulfur, ash, heavy
metals).
The properties of fossil fuels have been studied system-
atically since the first half of the nineteenth century, and
some classical accounts still appear useful (Sexton 1897;
Poole 1910). Modern knowledge of fossil fuels is
reviewed comprehensively in Francis and Peters (1980),
Bartok (1991), Berkowitz (1997), and Odell (2004),
and in detailed treatments focusing on coals (C. L.
Wilson 1980; Ward 1984; Berkowitz 1985; Yang 1997;
L. P. Thomas 2002; WCI 2005), and crude oils and nat-
