The idea that economic growth generates
pollution problems, but simultaneously provides the means to
clean up most of them and even to improve on earlier conditions,
is probably too counterintuitive to be readily accepted by most
people. It is nonetheless backed up by much historical evidence.
A brief discussion of the causes underlying forest regrowth and
improvements in air and water quality in advanced economies can
be illustrative in this respect.
While historically severe localized problems drew much
attention, some evidence suggests that air quality improved
significantly in many American cities for decades prior to the
passage of the 1970 Clean Air Act. Suspended particulates in
Cincinnati thus declined between 1946 and 1951, while
atmospheric visibility markedly improved in Pittsburgh between
1946 and 1955 (Goklany, 1999). In the late 1960s, the sulfur
dioxide content of the air in some American cities was only one-third
or one-fourth of what it had been before World War II (Crenson,
1971), while the rate of pollution reduction in the 1970s might
have been less than the one observed in the 1960s (Crandall,
1983). Indeed, according to Goklany (1999), by the 1960s the
smoke problem was virtually solved in most American urban areas.
Similar trends were also observed in London and other places,
with turning points usually occurring at the beginning of the
twentieth century (Brimblecombe, 1987).
Air quality improvements during this period can be credited
mostly to fuel switches (from coal to heavy oil, natural gas,
hydro-electricity and nuclear power generation) that took place
for purely economic reasons (Ausubel, 1991), but also to some
extent to increased efficiencies of control of smoke and dust
pollution in industries and power plants. For example,
nationwide estimates of overall dust collection efficiency for
power plants, which had been 40% pre-1940, had climbed to 75% by
1940, over 80% by 1950, 90% by 1960 and 95,5% by 1966 (Goklany,
1999)(2).
Similar trends can be observed for water quality. For example,
Freeman (1995/1990: 114), referring to the EPA's first National
Water Quality Inventory conducted in 1973, points out that there
had been substantial improvement in water quality in major
waterways in the 1950s and 1960s, at least in regard to organic
wastes and bacteria, much of which could be traced back to the
construction of sewage systems. This emphasis on organic
pollution can be explained by the spreading influence of the
germ theory of disease in the late 19th Century which focused
the attention of public health officials and sanitary engineers
on sewage as a much more serious health threat than inorganic
industrial discharges. Of course, as Cumbler (1995) points out,
this emphasis might have also resulted at least in part from
political expediency.
|