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

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

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

In Scandi all tap water is great. Sell SAS water bottles onboard which are made to be reused = able to buy for points, pre-order as well. And then load tap water onboard.

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

Using hydrogen tanks in the rear of the plane, for example. This could work on shorter routes such as domestic flights or intra-Europe.