Incentivize sustainable behavior, e.g. a small reward for bringing your own coffee cup. This can also be sold by SAS in the Eurobonus store or in flight.

Change plastic luggage-trays at fast-track for sustainable (but durable) trays of reused plastic or other cyclic material

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

Instead of making passengers pay for biofuel, issue carbon credits for the emissions avoided by using biofuels instead of conventional aviation fuel.

Flying less emits less CO2. Thereby minimizing the impact on the planet.

Let it be easy to take steps when buying bio-fuel.