## Appendix A.1.2. Results
### Assessment Method  
The network-related OIs are analyzed regarding their climate mitigation potential in terms of reduction in ATR20 and ATR100. This is modeled either with an optimization of dedicated airline networks by considering not only profit but also climate impact or by splitting a mission with an intermediate stop for refueling in different scenarios (Figure 10). As those considerations typically influence long-term decisions, an aggregated climatological assessment approach is selected instead of incorporating time and weather-dependent effects on detailed missions. An annual European flight plan is investigated either with respect to certain airline types or all long-haul flights from the European network, which are suitable to ISO.  
Trajectory modeling is performed with Reduced Emission Profiles (RedEmP) as derived from standardized TCM calculations applying BADA4 aircraft performance data [82; 85] in combination with fuel-flow correlation methods to estimate emission quantities along standardized missions [87] for every possible combination of origin, destination, and aircraft. Climate impact assessment is performed with the climate chemistry response model AirClim [77; 91] incorporating background emissions defined in a BAU scenario [8].  
The modeling scenarios and the underlying flight network varies between the two investigated measures. On the one hand, airline network optimization problems involve a wide range of decisions, e.g., regarding fleet assignment, crew scheduling, route planning, and flight scheduling [92]. To address this complexity, a multi-agent optimization model is used to capture the interactions between different agents and optimize decisions for the entire network [31] incorporating factors such as weekly demand distribution or capacity constraints for the selected representative airlines KLM, TAP, and easylet. On the other hand, the best configuration with regard to the climate impact is selected from a set of possible intermediate stop airports and preferred cruise altitudes in the course of ISOC.  
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline  & \multicolumn{2}{l}{**Climate Mitigation Potential**} & \multicolumn{2}{l}{**Change in DOC**} & \multicolumn{2}{l}{**Limitations**} \\ \hline \multirow{3}{*}{**LOSL [45; 70]**} & \(\bullet\) & \(-8.7\%\) on 16 June 2018 & \(\bullet\) & \(+3.0\%\) on 16 June 2018 & \(\bullet\) & North Atlantic flight sample \\  & \(\bullet\) & \(-16.1\%\) on 11 December 2018 & \(\bullet\) & \(-2.5\%\) on 11 December 2018 & \(\bullet\) & Asessment of pulse-ATR20 \\ \hline \multirow{3}{*}{**FREE [47]**} & \multirow{3}{*}{\(-24.4\%\) on 11 December 2018} & & \(\bullet\) & Flights that use the focused & \\  & & & & & en-route airspace (EDUU) in & \\  & & & & & ECAC area on the selected day & \\  & & & & & & \(\bullet\) Assessment of pulse-ATR20 \\ \hline \multirow{3}{*}{**WIND [47]**} & \(\bullet\) & Wind-optimal: \(-24.1\%\) & \(\bullet\) & Wind-optimal: \(-4.3\%\) & \(\bullet\) & Flights that use the focused \\  & \(\bullet\) & Emission-optimized: \(-28.0\%\) & \(\bullet\) & Emission-optimized \(-2.9\%\) & & en-route airspace (EDUU) in \\  & & on 11 December 2018 & & on 11 December 2018 & \(\bullet\) & ECAC area on the selected day \\ \hline \multirow{3}{*}{**CLIM [48]**} & \(\bullet\) & LHR-JFK: \(-10.9\%\) & \(\bullet\) & LHR-JFK: \(+5.5\%\) & \multirow{3}{*}{Four city pairs on selected day, departure only from ECAC area} \\  & \(\bullet\) & FRA-YYZ: \(-14.8\%\) & \(\bullet\) & FRA-YYZ: \(+1.5\%\) & & \\  & \(\bullet\) & SNN-JFK: \(-8.9\%\) & \(\bullet\) & SNN-JFK: \(+2.6\%\) & & \\  & \(\bullet\) & MAD-SJO: \(-12.1\%\) & \(\bullet\) & MAD-SJO: \(+7.1\%\) & & \\  & & on 11 December 2018 & & \(\bullet\) & Assessment of F-ATR20 \\ \hline \hline \end{tabular}
\end{table}
Table 10: Summary of results from individual assessment of trajectory-related OIs [45; 47; 48; 70].