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

Donate unused food and beverages after flights and try to get closer to zero food waste.

Add green flights on some departures. nothing is served on these flights, only hand luggage is allowed, but you earn more Eurobonus points if you choose such a departure.

Give more Eurobonus point to sustainable destinations, by ranking airports and/or destination

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

Develop solar-powered aircraft with energy storage systems to enable fully renewable, zero-emission long-haul flights within the next decade.