1. Non-CO2 impacts have to be fully accounted for by the industry, by institutions and governmental bodies and by UNFCCC within the framework of the Paris Agreement.
2. Known measures to mitigate non-CO2 impacts, such as contrail avoidance and the adoption of lean-burn low NOx engines, must be pursued immediately in addition to CO2 mitigation.
3. Research and development of operational and technological improvements, which give the same importance to the reduction of non-CO2 impacts as to CO2 reduction, must be intensified and funded.
4. Air traffic must not be allowed to return to pre-Covid-levels. Accordingly, bailouts, subsidies, tax exemptions, and the construction and expansion of airports must cease. Governmental measures for a deep, sustained reduction of flights and for substituting alternatives like rail travel and renewably-powered ships must be quickly implemented.