Environmental Engineering Reference
In-Depth Information
TPES ignores it. On the economics side are not only
questionable currency conversions (official exchange rates
undervalue GDPs of low-income economies; PPPs over-
value them) but the fundamental question of what GDP
measures and hence attempts to consider more revealing
alternatives (OECD 2006). Nothing has changed since
Rose (1974, 359) noted, ''So far, increasingly large
amounts of energy have been used to turn resources
into junk, from which activity we derive ephemeral bene-
fit and pleasure; the track record is not too good.'' And
the balance looks even worse when the extensive envi-
ronmental destruction caused by this consumption is
included in the overall appraisal of this record.
Quality considerations are best illustrated by the fact
that no fuel can confer economic benefits like efficiency,
productivity, and flexibility better than electricity (NRC
1986; Smil 2005a). Its high final conversion efficiencies,
precise control, focused applications, and fractional uses
offer an incomparable combination of advantages. Mod-
ern mass production demanding flexibility, precision,
and expansion is unthinkable without electricity, as
are modern health services, household comforts, and en-
tertainment. Only a small (but steadily rising) fraction of
electricity is used to design, manage, route, regulate, and
improve the information that now suffuses modern civili-
zation, and the formulation of the equivalence between
energy and information opened the way for rigorous
quantitative studies of this critical energy flux (Shannon
and Weaver 1949). But applying this approach to econo-
mies at large is neither easy nor necessarily useful because
the effort to minimize the energy to information ratio
(J/bit) keeps colliding with inherent, often culturally
driven inefficiencies of human behavior.
A closer look at energy-GDP links also reveals that
a given level of economic well-being does not require a
fixed level of TPES. Different energy intensities (EIs) of
national economies (annual TPES/GDP) show consider-
able scatter within both low- and high-income groups.
British EI shows a steady secular decline following the
rapid rise caused by the adoption of steam engines and
railways between 1830 and 1850 (Humphrey and Stani-
slaw 1979). Canadian and U.S. EIs followed the British
trend with a lag of 60-70 years (fig. 12.2). Between
1955 and 1973 the U.S. EI was flat (fluctuating just
G2%) while the real GDP grew 2.5-fold, but then the
ratio's decline resumed, and by 2000 it was below the
1950 level. In contrast, Japanese EI rose until 1970, as
did the Chinese rate, which since that time has fallen
faster than at any previous time (fig. 12.2).
In the year 2000 the EIs of the world's most impor-
tant economies spanned a considerable range of values.
In G7 countries they ranged from less than 7 MJ/1000
$ for Italy and Japan to more than 13 MJ/1000 $ for the
United States and over 18 MJ/1000 $ for Canada. In
contrast, EIs were in excess of 30 MJ/1000 $ for India
and China. National EIs confirm and reinforce some of
the widely held snapshot notions: efficient Japan, rela-
tively wasteful United States, China with a long modern-
ization road ahead. Advanced extraction, processing,
and manufacturing techniques reduce national EIs, and
countries with relatively low intensities should enjoy
some important economic, social, and environmental
advantages.
But these distillations of complex realities are sim-
plistic and misleading if interpreted in a naive, ahistori-
cal fashion. Explanations of national EI differences are
multifactorial, ranging from climate to recreational hab-
its, but most of the gap can be accounted for by
the makeup of primary energy consumption and by the
structure and efficiency of final conversions. Higher
