The strong and continuing increase in airtraffic,the plans to build supersonicair- craftsand hypersonicspace-transportsystems,the developments ofhydrogentech- nology, andthe generalconcern onglobalchangeshave raised questionson effects of emissions from air traffic on the environment and especially the atmosphere aboveand shortlybelowthe tropopause. What are the consequences of watervap- our emissions on the formation of high clouds and global c1imate?What are the possibleeffectsofemissions on the ozonelayerin the stratosphere and uppertro- posphere?Which technological developments can help to reducethe emissions? These questions get increasing attention in the public. Some previous meetings of scientific experts have shown that the topic is of high interest but most questions cannot be answered yet to asufficientdegree. More research is necessaryand the topic requires interdisciplinarycooperation. Moreover,there is a need to document the basic knowledge required to assess possible consequences of increasing and changingtraffic.With respect to possible global changes,airtraffic at cruising alti- tude seemsto have the mostimportantinnuence and itbecomes necessaryto con- sidertechnological alternatives. The German Aerospace Research Establishment (DLR) has initiated aseries of seminars on fundamental problems ofsciences inwhich DLR is envolved. Previous seminarsconsidered: 1984 NonlinearDynamicsofTranscritical Flows 1985 UncertaintyandControl 1986 Artificial Intelligenceand Man-Machine-Systems 1987 Parallel Computing in Science and Engineering 1988 HydrocarbonOxidation 1989 Optlmizatlon,Methods and Applications, Possibilities andLimitations This bookcontainsten paperswhichhad been preparedfor presentationatthe 1990 DLR-Seminaron AirTrafficand the Environment- Background,Tendencies and Potential Global AtmosphericEffects. At the seminar, an additional paper is to be presented by Dr. Dieter H. Ehhalt.
