"Present energy policies are inconsistent with reducing greenhouse gas emissions and limiting global climatic change." - Dean Abrahamson University of Minnesota, USA 75% of the carbon dioxide added to the atmosphere through fossil fuel burning. However, from 1950-1984 the carbon dioxide released by burning of fossil fuels in developing countries increased at a rate of 2.2% per year. While still small in absolute terms, the African consumption of fossil fuels is increasing rapidly. Of the greenhouse gases, carbon dioxide is responsible for 66% of the global warming. The pre-industrial concentration of atmospheric carbon dioxide was 280 ppm; in 1989, it was 351 ppm and by the year 2030 it is expected to rise to 560 ppm. Global Warming and Climate Changes The most direct effect of the increased trapping of heat radiation is a global warming. The warming will not be globally uniform but will differ significantly between geographical regions; in addition, the warming may vary between seasons. As a result, the altered temperature gradients will change the pattern of winds and precipitation distribution regionally. The details of these localized changes are not clearly understood. It is expected, however, that the interiors of continents will become drier and climatic zones will shift, displacing current patterns of agricultural production. The observed global temperature records, including ocean and land readings, reveal a warming trend during this century of a magnitude within the range predicted by models. Furthermore, the latter half of the 1980s registered the warmest temperatures on record. The warming of the oceans is expected to lead to a rise in the sea-level through thermal expansion, as well as addition of water through the melting of ice sheets and glaciers. Major Scientific Issues to be Resolved Respiration. The biosphere controls the atmospheric concentration of greenhouse gases such as carbon dioxide and methane, and biotic processes such as respiration are regulated by ambient temperature. Interactions between the biosphere and climate can play a significant role in determining the future concentrations of greenhouse gases like carbon dioxide and methane. The possibility and effects of increased respiration, plant growth and decomposition need to be assessed. Clouds. One of the largest sources of uncertainty in predicting regional and global climatic changes is the response of clouds to the warming. The tropical monsoon cloud-systems are one of the major factors regulating the global heat budget and these clouds respond significantly to small changes in ocean temperatures. Analysis of the role of clouds is needed. "The day of complete scientific certainty may not come." - Andronico Adede United Nations Office of Legal Affairs, New York, USA 5