The scientific work described in this book is the result of an international coopera­ tion of over 60 researchers from many different European countries over more than 10 years. Considerable advances have been made in the development, appli­ cation and improvement of methods and models for the calculation of emissions. Work on the quantification of uncertainties of emission data could be enhanced and carried out and uncertainty assessments conducted. The developed methods present the current state of the art in this field. Collaboration of teams has taken place under the EUROTRAC, the EUREKA project on the transport and chemical transformation of trace constituents in the troposphere over Europe extensive and networks of joint research work could be established across Europe. The editors wish to express their gratitude to all contributing authors and their teams for their cooperation, without which this book could never have been com­ piled. Furthermore, authors and editors alike are much obliged to the International Scientific Secretariate (ISS) of EUROTRAC, in particular Dr. Pauline Midgley, for outstanding support in the preparation of this book.