When the crew collects trash before landing, why not make separate rounds for collecting, cans, plastic cups, paper, etc instead of collecting all trash in the same bin.

Display a flight's estimated carbon footprint on the SAS booking site so travellers can choose the most carbon-efficient routing.

And give more SAS bonus points to travelers who book with biofuel. Incentives!

Instead of opt-out for food on the plane plane that is included in ticket, make it opt-in.

Meals included in the ticket fare are by default vegan (should be cheaper for SAS) and if meat dish is desired then it is a special order at an additional cost.

Do not carry tax-free goods on flights. Use as online service and if necessary in partnership with partners allowing pick-up at airports.