Environmental Engineering Reference
In-Depth Information
100
-0.94%/yr
Energy Intensity:
Traditional + Commercial Fuels
-2.7%/yr
Energy Intensity:
Commercial Fuels Only
10
1800
1850
1900
Year
1950
2000
fig. 6.1
Energy intensity of the US economy in megajoules per
dollar from
to
. (Courtesy of Professor S. Fetter,
University of Maryland. ©
Steve Fetter, Climate Change and
the Transformation of World Energy Supply. Stanford,
Center for International Security and Cooperation)
energy to run a bank than a steel mill, though both may
produce the same increment of GDP). This is particularly
important because two of the world
s largest countries by
population, China and India, are undergoing rapid eco-
nomic growth. At the beginning of their growth cycles,
industry dominates over services and processes tend to be
relatively inef
'
ciency
(reducing energy intensity) on energy demand are also
important in estimating the worldwide demand for energy
in the future.
Figure
cient. The effects of improving ef
shows the energy intensity of the US econ-
omy going back to the year
.
when horsepower meant
literally the number of horses used. The main sources of
