Reduce taxi time,(for larger aircraft) continuous climb and decent, optimized flightpaths, implement greener lounges (green electric), more points for greener choices.

Dedicated recycling bins in galley/ head for passengers to use during non-service times

I would use my skills in optimization and deep learning to learn what frequenzies and time schedules that maximizes the load factor of each aircraft in the fleet.

For flights with a lot of empty seats, open more award seats short time before departure.

Invite all travellers to bring their own coffee cup.

SAS connects Scandinavia with Europe, through hubs and trains. Fly to a hub, get a train to your destination.