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Preface Annex 1
CHAPTER 2: ATMOSPHERE
Lead Author: Njeri Wamukonya
Africa is endowed with diverse and abundant atmospheric resources. These resources include rainfall, air, solar radiation or insolation, and wind. Unlike land and marine resources, atmospheric resources are found in all African countries, although at varying levels, distribution and frequency.
Atmospheric resources provide life-supporting goods-and-services. The air contains oxygen, carbon dioxide and nitrogen that are essential for life and livelihoods. The clouds, with their accompanying lightning phenomenon and rainfall, play a critical role in supporting life on Earth. Rainfall is a source of water for people, animals and plants, and for rain-fed agriculture. The ozone layer, found in the stratosphere, protects human beings from ultraviolet radiation that is likely to cause cancer. Solar insolation provides light and energy. The sun, wind and rivers are sources of energy for direct use or electricity generation.
The northern and southern countries in Africa receive little rainfall, below 1 000 mm per year. The equatorial countries receive over 1 000 mm of rainfall on average. Higher speed winds are generally found in the southern and northern parts of the continent. Virtually all countries in Africa receive over ten hours of sunshine a day, providing good potential for solar energy generation. The air in Africa, except in major industrial cities, is relatively clean.
Atmospheric resources offer a variety of opportunities for sustainable development. Air pollutants including soot and dust, greenhouse gases (GHG), chlorofluorocarbons (CFCs), and heavy metals affect the quality of air and threaten the goods-and- services provided by the atmosphere. These pollutants contribute to climate change, climate variability, depletion of the ozone layer, and low air quality. Climate variability and climate change manifest themselves in global warming, and extreme weather events including floods, droughts, heat waves and typhoons. These phenomena affect human well-being through increasing the incidence of diseases, affect land and marine productive systems from which livelihoods are derived, and destroy infrastructure.
Thus, threats to atmospheric resources undercut development opportunities. Mitigating the causes and impacts of potential threats is important: Africa needs to develop appropriate policy and action. Investing in programmes and businesses that mitigate the effects of climate variability, climate change and air pollution presents opportunities for sustainable development. There are also benefits that can be derived in reversing degradation of atmospheric resources.