Climate Change

In 1995, the Intergovernmental Panel on Climate Change (IPCC), a panel of experts assembled by the United Nations, concluded after detailed scientific reviews that "the balance of evidence suggests a discernible human influence on global climate." (IPCC, 1996). This human influence on the climate is mainly due to the emissions of three greenhouse gases (GHG) - carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), of which CO2 is the most significant. Energy production and use is responsible for 80% of all anthropogenic GHG emissions and even in fairly optimistic scenarios, carbon emissions from burning fossil fuels (in the form of CO2) are predicted to increase quite dramatically. Indeed, according to the most likely IPCC scenarios, they will double from a total of 6.5 Gigatons of carbon today to 13.8 Gigatons by 2050 (IPCC. 1992). Current patterns of land-use and energy have been deemed responsible for the net atmospheric increases in greenhouse gases, which are predicted to result in moderate to severe changes in regional and global temperature, precipitation, soil moisture and sea level.

Figure 5 Air Pollution in Megacities of the World

Source: UNEP/WHO, 1992

Changes in temperature and water availability will particularly affect the ecosystems of tropical forests and mountainous regions, reduce soil stability in some areas, increase the stress on fisheries and harm wetlands. In turn, there could be further reductions in natural water availability in areas already under stress. There are also likely to be adverse impacts on human health due to increased exposure to very hot weather and to severe weather events, increased risk of transmission of vector-borne and contagious diseases, and possible impairments in nutritional status. Some of the most catastrophic impacts are expected to be increased hurricane intensities in areas already prone to hurricane damage, which happen to fall across many parts of the developing world, including south and south-east Asia, the south Pacific and the Caribbean. In addition, rising sea-levels and increases in flooding, coastal erosion and storm frequency or intensity will put tens of millions of people at risk, especially in island states and low-lying countries such as the Maldives, Egypt and Bangladesh. People living in poverty are likely to be the worst affected by all these impacts, because they typically lack the resources required to make even marginal allowances (such as purchasing insurance) for increases in generalised risk to human health and habitat. Significantly, the impacts of the warming are likely to lead to higher economic costs for developing countries than for industrialised countries. Warming of 2-to-3 degrees Celsius by 2100 has been estimated to cost developing countries 5-to-9% of their GDP (IPCC, 1996).