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.

Create an ability to share a seat in your car with other passengers on the flight. It's better than everyone riding their car.

Option to remove included luggage when booking. This will help SAS to predict load and be more efficient.

Offer obsolete products to travelers

Collaborate with public transport companies at popular destinations to reduce car usage.

Use travellers feces from flights as a bioproduct. As fuel or to something else useful.