The North Atlantic Treaty Organization (NATO) established the "Committee on the Challenges of Modern Society" (CCMS) at the November 1969 meeting of the North Atlantic Council. The CCMS was charged with developing meaningful environmen tal and social programs that complement other international pro grams, and with showing leadership, first, in solution of exist ing problems and, second, in development of long-range goals for environmental protection in the NATO sphere of influence and in other countries as well. A first Pilot Study on Air Pollution was initiated by the CCMS at its inaugural meeting in December 1969. It resulted in documents about the definition of criteria for the effects of air pollutants as well as the development of assess ment methods for air quality in urban areas. A second Air Pollution Pilot Study (1975-1979) worked out the basics for setting up assessment methods for emissions inven tories, techniques for the practical application of meteorologi cal diffusion models as well as the development of guidelines for an Air Quality Management System (AQMS). Within this second Air Pollution Pilot Study attention to modelling concentrated on the Gaussian Plume Model. A third Pilot Study on Air Pollution Control Strategies and Impact Modelling then was initiated in 1979 and started in 1980.

Finishing this book is giving me a mixture of relief, satisfaction and frus tration. Relief, for the completion of a project that has taken too many of my evenings and weekends and that, in the last several months, has become almost an obsession. Satisfaction, for the optimistic feeling that this book, in spite of its many shortcomings and imbalances, will be of some help to the air pollution scientific community. Frustration, for the impossibility of incorporating newly available material that would require another major review of several key chap ters - an effort that is currently beyond my energies but not beyond my desires. The first canovaccio of this book came out in 1980 when I was invited by Computational Mechanics in the United Kingdom to give my first Air Pollution Modeling course. The course material, in the form of transparencies, expanded, year after year, thus providing a growing working basis. In 1985, the ECC Joint Research Center in Ispra, Italy, asked me to prepare a critical survey of mathe matical models of atmospheric pollution, transport and deposition. This support gave me the opportunity to prepare a sort of "first draft" of the book, which I expanded in the following years.

This is the first in a new series of publications arlslng out of the work of the Committee on Challenges of Modern Society of the North Atlantic Treaty Organization. The CCMS was established in 1969 with a mandate to examine practical ways of improving the exchange of experience among mem ber nations of the Alliance in the task of creating a better envir onment for their societies. It was charged with considering "spe cific problems of the human environment with the deliberate objec tive of stimulating action by member governments". It may come as a surprise to some that NATO - generally thought of as being an organization devoted solely to matters of defence - should concern itself with the environment at all. But this is to overlook Article 2 of the North Atlantic Treaty of 1949, which expressly provides that member count ries should contribute towards the furt her development of peaceful and friendly internat ional relations by promoting conditions of stability and well being. This concern is reflected in many non-military areas, in addition to the environmental one. I wish the present volume, which has been edited by the Bel gian Prime Minister's Office for Science Policy Programming, every success.

In 1949, when the North Atlantic Treaty was ratified, one of its articles explicitly noted '1hat member countries should contribute towards the further development of peaceful and friendly international relations." Specific problems related to the human environment were addressed by the Committee of Challenges of Modern Society (CCMS) of NATO, established in 1969. This provided a framework within which a series of International Technical Meetings (ITMs) on Air Pollution Modelling has been held. This volume documents the proceedings of the 18th meeting in this series. Science, like the arts and sports, provides an ideal vehicle for "developing peaceful and friendly international relations". National boundaries have never been barriers to the movement of air pollution, and fortunately this has also proved true of scientists studying the transport of air pollution. It is thus satisfying to record that since the mid-seventies it has been commonplace to find Eastern European scientists among attendees at the ITMs which have (in a very modest way) participated in a precursor to the process which has led to historical changes in Europe and which will undoubtedly lead to a tremendous increase in personal and intellectual exchange on a worldwide basis.

Proceedings of the Millennium NATO/CCMS International Technical Meeting on Air Pollution Modeling and its Application, held May 15-19 in Boulder, Colorado. This volume is the latest in a series of proceedings dating back to 1971. The book addresses the problem of air pollution and reports the latest findings and developments in air pollution modeling, from a truly international list of contributors.

AND CONCLUSIONS OF THE WARSAW II MEETING ON ATMOSPHERIC COMPUTATIONS TO ASSESS ACIDIFICATION IN EUROPE JOSEPH ALCAMO and JERZY BARTNICKI International Institute for Applied Systems Analysis Schlossplatz 1, A-2361 Laxenburg, Austria (Received June 1, 1988; revised June 20, 1988) Abstract. Three topics are discussed in this report: sensitivity/uncertainty analysis of long range transport models, the interface between atmospheric models of different scales, and linkage between atmospheric and ecological models. In separate analyses oflong range transport models, it was found that uncertainty of annual S deposition was mostly affected by uncertainty of wind velocity, mixing height and wet deposition parameterization. Uncertain parameters collectively caused S deposition errors of around 10-25% (coefficient of variation) in the models examined. The effect of interannual meteorological variability on computed annual S deposition was relatively small. Different methods were presented for combining models of regional and interregional scale. It was found to be more important to include interregional information in regional-scale models for annual computations compared to episodic computations. A variety of linkage problems were noted between atmospheric and ecological models. The vertical distribution of pollutants and 'forest fittering' of pollutant deposition were found to be important in ecological impact calculations but lacking in the output of most interregional atmospheric models.

Over the last decade, economists have increasingly recognized the role of meta-analysis and value transfer in synthesizing knowledge and efficiently exploiting the existing pool of knowledge. Comparative Environmental Economic Assessment explores the potential significance of using these techniques, particularly in environmental economics. Both meta-analysis and value transfer constitute major research tools which efficiently use knowledge previously acquired from other studies. The book focuses on the potential role and usefulness of these tools in environmental economic research, and goes on to address their validity, relevance and applicability. A future agenda for research is also illustrated.

This is the first publication to offer a comprehensive and balanced view of atmospheric acidity. It is organised in three sections. The first part consists of reviews of sources of acidic compounds, the second part outlines the environmental consequences and the final part discusses the technological, legal and political aspects of control strategies.

This book states that current developments in air pollution modeling are explored as a series of contributions from researchers at the forefront of their field. This newest contribution on air pollution modeling and its application is focused on local, urban, regional and intercontinental modeling; long-term modeling and trend analysis; data assimilation and air quality forecasting; model assessment and evaluation; aerosol transformation. Additionally, this work also examines the relationship between air quality and human health and the effects of climate change on air quality. This work is a collection of selected papers presented at the 38th International Technical Meeting on Air Pollution Modeling and its Application, held in Barcelona, Spain, Oct 18–22, 2021. The book is intended as reference material for students and professors interested in air pollution modeling at the graduate level as well as researchers and professionals involved in developing and utilizing air pollution models.