This report provides accurate, unbiased, policy-relevant information to serve the aviation industry and the expert and policymaking communities. This report considers gases and particles such as carbon dioxide, methane and ozone gases that are emitted by aircraft into the upper atmosphere and the role that they play in modifying the chemical properties of the atmosphere and initiating the formation of condensation trails (contrails) and cirrus clouds. This report also examines how the radiative properties of the atmosphere can be modified as a result, possibly leading to climate change and how the ozone layer could be modified, leading to changes in ultraviolet radiation reaching the earth's surface. This report further attempts to project future growth of aviation emissions. It also considers how potential changes in aircraft technology, air transport operations and the institutional, regulatory and economic framework might affect emissions in the future. Current and future impacts of subsonic aviation and radiation forcing and UV radiation are thoroughly examined. This section lays emphasis on carbon dioxide, ozone, methane, cirrus clouds, sulfate and soot aerosols among others. Climate effects and effects of subsonic aircrafts on UV-B are also examined. This report further presents various options to reduce emissions and impacts suitable for fuel, operational, regulatory, and economic functions, aircraft and engine technology options. It briefly outlines various issues that would need to be addressed in the near future so as to reduce scientific uncertainty that has limited scientists' ability to project aviation impacts on climate and the ozone.