Environmental Engineering Reference
In-Depth Information
11
E
NVIRONMENTAL
C
ONSEQUENCES
Metabolism of Fossil-Fueled Civilization
Shall I not have intelligence with the earth? Am I not
partly leaves and vegetable mold myself?
Henry David Thoreau, Walden (1854)
their functioning, heterotrophs (particularly microbes
and fungi) as the principal controllers and processors of
key nutrient flows in ecosystems.
These parallels also hide many substantial differences.
Most important, all higher heterotrophs are incessant
carbon oxidizers because their brains die in a matter of
minutes without oxygen, whereas the oxidation of fossil
fuels proceeds in spells that range from minutes for short
car drives to more than a dozen years in modern coke-
fueled blast furnaces. Even some very large heterotrophs
leave only fleeting footprints on the landscape they in-
habit, but many infrastructures of fossil-fueled societies
change the land cover radically, some even irreparably.
Heat rejection rates of fossil fuel and electricity con-
versions vastly surpass anything that even densely packed
organisms can ever produce. Specific material inputs
needed to maintain high-energy societies are far above
the rates needed to support heterotrophic life. And the
extent of human interference in biogeochemical cycles
The metabolic parallels between the functioning of fossil-
fueled civilization and heterotrophic life are clear. They
both have extensive footprints: in the first case, land
claimed by extraction, transportation, and conversion of
fuels and generation and transmission of electricity, in
the other case often large and fiercely defended home
ranges. They both oxidize carbon, high-energy societies
via the combustion of fuels, heterotrophs via aerobic res-
piration. They both require water, and both heat their
surroundings. They depend on steady inflows of raw
materials, structural components (metals, wood, con-
crete) in the first case, essential macro- and micronutri-
ents in the second. And both play major roles in the
planet's key biogeochemical cycles, fossil-fueled civiliza-
tion as a growing source of worrisome interference in
