During the last few decades anthropogenic activities in the industrially advanced countries have outcompeted nature in changing the global environment. This is best illustrated for example by the polluted lakes in Scandinavia and Canada, associated with acid deposition from fossil fuel combustion. One of the major challenges mankind is confronted with in the field of energy consumption is undoubtedly to ensure sustainability - a goal that requires improved management of natural resources and a substantial reduction of the noxious emissions which are dangerous to health and the environment. The threat of global climate change due to pollutant emissions causes se­ rious concern to many nations, and reaching an international consensus is likely to take some time. Carbon dioxide emissions have slowed only marginally in industrialized countries during the last few years, but have increased significantly in most developing countries due to increases in energy demand and the increasing use of fossil fuels, which remain the most readily available energy sources today. Unfortunately, far from learning lessons from the negative experiences of developed countries, many developing countries are taking the same path to development which has turned out to result in serious environmental consequences. This book gives an overall picture of the general state of the world's aquatic resources - rivers, lakes, wetlands and oceans - and of the atmospheric changes taking place in the troposphere and the stratosphere. Both ozone depletion in the stratosphere, leading to a greater incidence of the harmful ultraviolet-B radiation on the Earth's surface, and the adverse impact of increasing ground-level ozone are described in the light of recent research. The summarized scientific findings and views help to identify and implement sound preventive, corrective and remedial measures to cope with today's environmental problems.