Introduce a "minimal comfort" seating class with basic amenities and reduced seat recline, allowing more passengers per flight and lowering per-person emissions.

Fill up empty seats by selling affordable return trips to unknown/secret destinations. Pick the destinations among those that have low occupancy close to departure time.

a better airline trolley for sorting garbage. Maybe with possibility for travellers to put in from the sides.

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

Help handlers submit more precise Target-Off-Block-Times for better CTOTs, to save fuel spent on ground waiting.

Keep your good clients - minimum 10 years as gold member gives you gold for life. Not necessarily 10 years in a row. Now 18 years with 1 missing in the middle = no go