Environmental Engineering Reference
In-Depth Information
Figure 4.3
The geography of acid rain in Europe and
North America
pollution required by the Clean Air Acts, the
CEGB in Britain erected 200 m high smokestacks
at its generating stations (Pearce 1982d).
Industrial plants and power stations in the United
States took a similar approach, increasing the
heights of their stacks until, by 1977 more than
160 were over 150 m high (Howard and Perley
1991) and by 1981, at least 20 were more than
300 m high (LaBastille 1981). The International
Nickle Company (INCO) added a 400 m
superstack to its nickel smelter complex at
Sudbury, Ontario in 1972 (Sage 1980). The
introduction of these taller smokestacks on
smelters and thermal electric power stations,
along with the higher exit velocities of the
emissions, allowed the pollutants to be pushed
higher into the atmosphere. This effectively
reduced local pollution concentrations, but
caused the pollutants to remain in the atmosphere
for longer periods of time, thus increasing the
probability that the acid conversion processes
would be completed. The release of pollutants
at greater altitudes also placed them outside the
boundary layer circulation and into the larger
scale atmospheric circulation system with its
potential for much greater dispersal through the
mechanisms of LRTAP. The net result was a
significant increase in the geographical extent of
the problem of acid rain.
THE GEOGRAPHY OF ACID RAIN
Total global emissions of the SO
2
and NO
X
, the
main ingredients of acid rain, are difficult to
estimate. Fossil fuel combustion alone produces
about 91 million tonnes annually (Hameed and
Dignon 1992) and other activities, both natural
and anthropogenic, add to that. The main sources
are to be found in the industrialized areas of the
northern hemisphere. Northeastern North
America, Britain and western Europe have
received most attention (see Figure 4.3), but
eastern Europe and the republics of the former
USSR—Russia, Ukraine and Kazakhstan along
with eastern and western Europe, emit a—are
also important sources. These republics,
combined total of some 54 million tonnes of SO
2
Source.
Compiled from data in Park (1987); Miller
(1984);
LaBastille (1981); Ontario: Ministry of the
Environment (1980)
