How you can influence the reduction of emissions during the flight:

• Choose direct flights for the flight.
• Choose low-cost carriers. After all, the more people on board, the lower the CO2 emissions per passenger.
• Use alternative modes of transport if possible.

How to reduce debris during flights:

• Use a reusable suitcase cover, not wrapped in polyethylene. Better yet, just put your suitcase in your luggage and don't forget that your suitcase is a cover for your things.
• Do not print the ticket, use the electronic version.
• Hotel reservation. Also, if necessary, use the electronic version.
• Take a reusable bowl with you. Later, it can be used on board the aircraft when the flight attendant will offer coffee or tea. 
• Your own water bottle. Remember how many disposable water bottles are removed at the checkpoint and later you go to Duty Free for another one.
• Take a snack with you. You can safely take an apple, dried fruit, sandwich, such in hand luggage is not removed.