The Geography Of Acid Rain

Total global emissions of the SO2 and NOX, 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 SO2

Figure 4.3 The geography of acid rain in Europe and North America

Figure 4.3 The geography of acid rain in Europe and North America

Acid Rain North America

Source. Compiled from data in Park (1987); Miller (1984);

LaBastille (1981); Ontario: Ministry of the Environment (1980)

Source. Compiled from data in Park (1987); Miller (1984);

LaBastille (1981); Ontario: Ministry of the Environment (1980)

Figure 4.4 Sulphur dioxide emissions in selected countries: 1970-89

7000 T

Figure 4.4 Sulphur dioxide emissions in selected countries: 1970-89

7000 T

Acid Rain Norway

CANADA U.K. JAPAN SWEDEN NORWAY

Source: Based on data in World Resources Institute (1992)

CANADA U.K. JAPAN SWEDEN NORWAY

Source: Based on data in World Resources Institute (1992)

every year, or almost double that produced in North America (Barrie 1986). In Asia, Japanese industries emit large quantities of SO2 (Park 1987), while the industrial areas of China are also major contributors. Annual emissions of SO2 in China average 15 million tonnes, but have been as high as 24 million tonnes (Glaeser 1990).

Sulphur dioxide emission levels in the western industrialized nations peaked in the mid-1970s or early 1980s, and have declined significantly since then (see Figure 4.4). In Britain, for example, the output of SO2 decreased by 35 per cent between 1974 and 1990 (Mason 1990). Similar declines in SO2 have been recorded for North America and western Europe, and that trend is likely to continue as new environmental regulations are introduced and enforced. In contrast, emissions of NOX continue to rise. This may be due in part to increased automobile traffic, but it also reflects the limited attention given to NOX reduction in most acid pollution control programmes. The trends are less clear and more difficult to forecast outside western Europe and North America. As long as the economic and political disarray continues in eastern Europe and the former Soviet Union, it is unlikely that pollution control programmes will be given top priority, and acid gas emissions are likely to remain high or even increase. Chinese economic development will continue to be fuelled by low-quality, sulphur-rich coal, leading to increased local and regional levels of atmospheric acidity (Glaeser 1990). In contrast, Japan—the leading industrial nation in Asia—was quick to install pollution control equipment to reduce SO2 and NOX levels in the 1980s (Ridley 1993), and the decline in emissions there is likely to continue. The problem of acid rain has received less attention in Asia than in Europe or North America, but a new study initiated in 1992 under

Figure 4.5 The geography of acid rain, showing areas with pH below 5.0

Figure 4.5 The geography of acid rain, showing areas with pH below 5.0

Geography Acid Rain
Source: After Park (1991)

the auspices of the World Bank has been designed to change that. The study will be based on a computer model called RAINS similar to one developed by the International Institute for Applied Systems Analysis for the European Community. Results from the model will allow researchers to alert Asian governments to the extent and intensity of the acid rain problem, and to recommend ways of dealing with it (Hunt 1992).

Acid emissions remain limited outside the major industrial nations, but concern has been expressed over growing levels of air pollution which may already have provided a base for acid rain in some Third World countries (Park 1987). The future extent of the problem will depend upon the rate at which these countries industrialize, and the nature of that industrialization. Experience in the developed world shows that other possibilities exist also.

For example, large conurbations—such as Los Angeles—with few sulphur producing industries, but with large volumes of vehicular traffic, have been identified as sources of acidic pollution (Ellis et al. 1984). Many developing nations are becoming rapidly urbanized, and, as a result, may provide increased quantities of the ingredients of acid rain in the future (Pearce 1982c). Thus, although at present the geographical distribution of acid rain is largely restricted to the industrialized nations of the northern hemisphere, it has the potential to expand to a near-global scale in the future (see Figure 4.5).

All of the areas presently producing large amounts of acidic pollution lie within the mid-latitude westerly wind belt. Emissions from industrial activity are therefore normally carried eastwards, or perhaps northeastwards, often for several hundred kilometres before being redeposited. The distance and rate of travel are

Figure 4.6 Annual emissions of sulphur dioxide (106 tonnes) in regions of the northern hemisphere that influence the Arctic

Figure 4.6 Annual emissions of sulphur dioxide (106 tonnes) in regions of the northern hemisphere that influence the Arctic

Brian Warming

Source: From Barrie (1986)

closely linked to the height of emission. Pollution introduced into the upper westerlies or jet streams is taken further, and kept aloft longer, than that emitted into the boundary layer circulation. For example, a parcel of air tracked from Toronto, at an altitude of 5,000 m, was found well out over the Atlantic, some 950 km east of its source, in less than 12 hours. In the same time span, a parcel of air close to the surface covered less than a quarter of that distance (Cho et al. 1984). In this way pollutants originating in the US Midwest cause acid rain in Ontario, Quebec and the New England states; emissions from the smelters and power stations of the English Midlands and the Ruhr contribute to the acidity of precipitation in Scandinavia.

The ultimate example of LRTAP is provided by acidic pollution in the Arctic, which has been traced to sources some 8,000 km away in North America and Eurasia (Park 1987). The winter atmospheric circulation in high latitudes causes polluted air to be drawn into the Arctic air mass in sufficient quantity to reduce visibility— through the creation of Arctic haze (see Chapter 5)—and increase environmental acidity. Sulphur dioxide and sulphate particles are the main constituents of the pollution which originates in the industrial regions of Eurasia and North America, with the former contributing as much as 80 per cent of the total (see Figure 4.6). The net result at locations in the Canadian Arctic is an atmospheric sulphate content during the winter months which is at least twenty to thirty times that of the summer months (Barrie and Hoff 1985). Slightly higher winter concentrations have been recorded in the Norwegian and Russian Arctic (Barrie 1986). This seasonal variation is reflected in the acidity of the precipitation and the snowpack, which varies from a pH of about 5.6 in the summer to 4.95.2 in the winter months (Barrie 1986).

The problem of acid rain obviously transcends national boundaries, introducing political overtones to the problem, and creating the need for international co-operation, if a solution is to be found. That co-operation was not easily achieved. Since the ingredients of acid pollution are invisible, and the distances they are carried are so great, it is not possible to establish a visible link between the sources of the rain and the areas which suffer its effects. It was therefore easy for polluters to deny fault in the past. The introduction of airborne sampling systems, using balloons (LaBastille 1981), or aircraft (Pearce 1982d) has helped to change that. Tracer elements added to a polluted airstream or source-specific chemicals allow emissions from a particular area to be followed until they are deposited in acid rain (Fowler and Barr 1984). Mathematical models developed in Europe also allow the final destination of specific acid emissions to be identified (Cocks and Kallend 1988). With such developments in monitoring techniques, denial of guilt becomes more and more difficult.

Survival Basics

Survival Basics

This is common knowledge that disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

Get My Free Ebook


Responses

  • Karen
    How does acid rain geography impact environment issue?
    8 years ago
  • mikko
    Where is acid rain a problem in the world?
    7 years ago
  • maria
    What five themes of geography is acid rain?
    5 months ago

Post a comment