Optimizing Global Flight Altitudes for Contrail Reduction: Insights from Open Flight and Weather Balloon Data

As the number of flights increases globally, the aviation industry faces a major challenge of reducing its climate impact. Contrails, besides contributing to global warming by trapping outgoing terrestrial radiation, can potentially offset the benefits of reduced emissions from optimized flight routes. In this study, we quantify contrail-forming flights on a global scale and evaluate the altitude deviations necessary to avoid contrail-forming regions, using a combination of the Integrated Global Radiosonde Archive (IGRA) data and flight data from OpenSky. The IGRA dataset contains measurements obtained by weather balloons and offers global coverage as well as a high vertical resolution. Mid-Western Europe, Eastern United States of America and Japan were identified as regions with both large volumes of air traffic and a high percentage of these flights forming contrails. These regions are also suitable for altitude changes of less than one kilometer to minimize contrail formation. In addition, regions are identified where a relatively small operational interventions can make a large climate impact.