Since the beginning of industrialization in the last century, a steady increase in energy consumption can be observed. At the same time, energy generation switched from wood and coal to predominantly oil, coal and natural gas. Soon, many countries became aware of the fact that the resources of fossil fuels, especially of oil and natural gas are finite. Diversification of energy sources became a requirement for the future. Governments expressed their concern by setting up natural energy programmes while international organisations undertook assessments of the global energy resources and possible rates of supply and substitution. When it comes to setting up energy policies, the following factors must be taken into consideration: population growth, level and nature of socio-economic activity, the costs of energy, the adequacy and reliability of supply, the availability of technology and supporting infrastructure, the success of energy conservation programmes and concern about the environment, safety aspects of production and use of energy as well as educational efforts toward a rational use of energy. When we express our most urgent concern, the long-term global energy provision, experts offer four interrelated partial strategies: - the strategy of rational use and conservation of energy - the strategy of using renewable energy sources - the coal strategy including coal gasification and liquefaction - the nuclear power strategy. Any strategy, however, for securing future energy supply has, from my point of view, to be thoroughly examined as to its impact on the environment.

by Joseph Weizenbaum Since the dawn of the age of computers, people have cursed the difficulty of programming. Over and over again we encounter the suggestion that we should be able to communicate to a computer in natural language what we want it to do. Unfortunately, such advice rests upon a misconception of both the computer and its task. The computer might not be stupid, but it is stubborn. That is, the computer does what all the details of its pro gram command it to do, i. e., what the programmer "tells" it to do. And this can be quite different from what the programmer intended. The misun derstanding with respect to tasks posed to the computer arises from the failure to recognize that such tasks can scarcely be expressed in natural language, if indeed at all. For example, can we practice music, chemistry or mathematics without their respective special symbolic languages? Yet books about computers and programming languages can be written more or less reasonably, even if they are not quite poetic or lyrical. This book can serve as an example of this art and as a model for anyone at tempting to teach inherently difficult subject matters to others. Klagenfurt, April 1995 Preface Striving to make learning to program easier, this book addresses primarily students beginning a computer science major. For our program examples, we employ a new, elegant programming language, Modula-3."

The present workshop is the third of a series of interna- tional conferences carried out within the framework of a research project on behalf of the Federal Minister of the Interior. Under this project, entitled "Impacts of Air Pollution on Climate", the Federal Environmental Agency (Umweltbundesamt) has sponsored so far: an international conference on "Man's Impact on Climate" at Berlin in June 1978, an international workshop on "Energy/Climate Interactions" at MUnster in March 1980; and an international workshop on "Food/Climate Interactions" at Berlin in December 1980, the results of which are pre- sented in this book. Based on the Federal Environmental Agency's report on "Im- pacts of Air Pollution on Climate", on November 11, 1979, the Federal Cabinet approved a climate research programme of the Federal Government. Details of the programme are being vlOrked out by a committee on climate research under the chairmanship of the president of the German Weather Service with the execu- tive office placed in the Federal Environmental Agency. This demonstrates that, by establishing a nationally co-or- dinated climate research programme, the Federal Government re- cognizes the importance of climate to the national economy. There- fore the Federal Republic of Germany intents to contribute appro- priately both to the comprehensive international programme of the United Nations on Climate and Environment, as represented by UNEP and WHO, and to the Climate Research Programme of the Commission of the European Communities.