Environmental Engineering Reference
In-Depth Information
Fuel use in the earliest complex civilizations was limited to burning wood and
crop residues, and even during the i rst centuries of the Common Era the average
per capita energy consumption in the Roman Empire, whose power was unmatched
in the West and whose territory extended to three continents, was no higher than
10 GJ per capita (Smil 2010c). By 1800 the British mean, the world's highest,
had reached about 50 GJ per capita (Warde 2007), and in 1900 the average U.S.
per capita energy (fossil fuels and wood) supply had surpassed 130 GJ (Schurr and
Netschert 1960). A century later the largest EU countries were, much like Japan, at
about 170 GJ, while the U.S. and Canadian per capita supply of primary energy
was running at twice that rate (BP 2011). And these are comparisons of gross inputs:
because of vastly improved energy conversion efi ciencies, the gains in terms of
actually available useful energy were at least three times higher.
Life expectancy at birth among the citizens of the Roman Empire was less than
25 years, and it was not until 1900 that the average for both sexes surpassed 50
years in the United States and various European countries; by 2010 it stood at
around 80 years in the world's most afl uent nations—and more than 70 years even
in China (UN 2011). And while per capita GDP is an imperfect measure of economic
well-being, its reconstructions for the Roman Empire (Maddison 2007; Scheidel and
Friesen 2009) yield only $500-$1,000 in today's monies, similar to the rates now
prevailing in the poorest countries of sub-Saharan Africa, while the 2010 averages
of large economies ranged from more than $40,000 for the United States, Japan,
and the EU's richest countries to about $4,000 for China (IMF 2010).
These indicators make it clear than when judged by its technical advances and
by its success in extending a comfortable standard of living to an increasing part
of global population, ours is an admirably accomplished civilization. In its quotid-
ian mental detachment from nature it sees its fate, not incorrectly, as highly depen-
dent on incessant and affordable supplies of modern energies in general and fossil
fuels in particular (hence the constant worries about “running out” or “peak oil”)
and on the availability of a wide range of nonenergy minerals. But i rst things i rst:
photosynthesis remains the most important energy conversion in the biosphere, and
without its products no heterotrophic life—including human civilization—would be
possible. Harvesting the biosphere is as quintessential for us as it was for our primate
ancestors, for the Paleolithic hominins, for the i rst sedentary societies engaged in
perfecting annual cropping eight millennia ago, or for the i rst great empires of
antiquity.
All of the intervening technical and scientii c innovations and the higher use
of energy would have been impossible without greatly expanded claims on the
