Framework and Tools for Environmental Management in Africa

6 Africa and Global Environmental Problems

Chapter 6 Africa and Global Environmental Problems Introduction In the previous chapter, there was detailed analysis of the environmental problems confronting the African continent, otherwise referred to as local and regional environmental problems in our continent. These problems, unlike the global problems we are about to discuss, have yet to receive adequate treatment for a better understanding of their impact on the African continent. Global environmental problems will not be analysed in such depth, because much has already been written on the subject. Global problems refer to widespread or global impacts, irrespective of the geographical areas of origin. Although their causes are largely linked to industrialised countries, and there is a very insignificant contribution from Africa, their impacts do not exclude this continent. Global environmental problems include air pollution, global warming and climate change, ozone layer depletion, acid deposition , nuclear waste and waste treatment. Air Pollution Air pollution is of very serious global concern (Figure 6.1); however at the global level, the causes are more closely linked with industrialised countries. However, it should be noted that every day, even in non-industrialised areas, the air is constantly polluted with smoke from kitchens, vehicles and industry, and through slash-andburn agriculture, and the indiscriminate burning of refuse. The gases contained in the smoke vary with the sources, but carbon dioxide (CO2 ) and carbon monoxide (CO) are the most common. Other smoke-borne substances include lead (PB), nitrogen oxide (NOX ), and sulphur dioxide (SO2 ). C O2 is a greenhouse gas responsible for global warming, which has already been discussed. CO2 is mainly produced by the incomplete combustion of carbon-containing fuels (coal, oil, charcoal or gas) and incineration of biomass or solid waste (Cunningham et al. 2003). Once it enters the respiratory system, it binds to haemoglobin and interferes with the transport of blood. The results are impaired perception , frequent headaches and drowsiness. Airborne lead is derived primarily from fuel additives, metal smelters and battery manufacturing plants. But leaded petrol is by far the greatest source in the 92 Framework and Tools for Environmental Management in Africa industrialised world. Direct inhalation of lead can lead to circulatory, reproductive, nervous and kidney damage in adults. Children and foetuses are susceptible to even lower levels of lead. They can face reduced birth weight, impaired mental and neurosensory development, and learning difficulties. Figure 6.1: 1890 Industrial Model of Smokestacks Pollutes the Atmosphere Source: Cunningham et al. 2003. Evaluating the cost of air pollution, as will be seen from the effects of the associated problems, is complicated. For instance, should valuation be limited to the damage of the biophysical environment? Where do the limits lie? Or should it include the secondary health, psychological, social and economic effects suffered by human communities as a result of the pollution? What values can be placed on the effects, which would honestly satisfy each and every affected individual? Must the value placed on these effects be the same as those resulting from natural disasters, or higher? Serious steps should be taken to arrest this problem, including the education of communities in appropriate waste management methods and appropriate technologies , for example, improved local stoves. Equally, there should be strict enforcement of regulations binding signatory countries to international conventions, which stress the need for radical improvement in industrial processes, with a view to reducing the emission of air polluting substances. There is also a need to transfer cleaner technology from the developed world to the developing nations, which mostly still maintain very old models of technology (Figure 5.7). 93 Africa and Global Environmental Problems Global Warming and Climate Change Scientific evidence shows that the temperature of the earth is increasing at an unprecedented rate. It is estimated that the global temperature has increased by 7ÚC over the last fifty years. This increase is due to what is referred to as the ‘greenhouse effect’. The greenhouse effect is the deflection back to the earth of heat trapped by some pollutants emitted into the atmosphere. These air pollutants, popularly known as greenhouse gases, include carbon dioxide, nitrous oxide, chlorofluorocarbons and methane. These gases are released from such human activities as the burning of fossil fuels, agriculture, deforestation, and industrial processes, and they vary in their contribution to the problem (Figure 6.2). Figure 6.2: Contribution to Global Warming of Various Types of Human Activity Source: Modified from Cunningham, et al., 2003. Figure 6.3 shows the relative...