NASA is trying to solve that problem by developing new fuel-efficient aircraft to make air travel more sustainable.
It just selected a round of new efficiency ideas for its Convergent Aeronautics Solutions project, and now the ideas will be tested to see if they're possible.
1. A better fuel cell for an electric plane
Fuel cells use hydrogen and oxygen to generate electricity. Normally, the hydrogen and oxygen have to be stored at really cold temperatures on the aircraft, but this new design would pull hydrogen from gas and oxygen from the air.
It would save more fuel and generate less emissions than current fuel cells
2. 3-D printed engine parts
Printing engine parts can make them lighter, smaller and able to hold more power.
3. Lithium-Air batteries for electric planes
Storing enough battery power on board is one of the biggest challenges in developing electric aircraft, but lithium-air batteries have the highest theoretical energy capacity for batteries.
The batteries suck in oxygen to react with lithium ions stored inside. The trick is developing a prototype that doesn't break down after a few recharges.
4. Foldable wings
The vertical tail is essential to keeping a plane on the runway if the engines fail, but when the plane is airborne, the tail just adds drag and makes the plane less efficient.
One solution is to design foldable wings that could help steer the aircraft when it's on the runway. That would allow airplane designers to create smaller tails.
These ideas will be tested for feasibility, and NASA will decide which can progress on to the research and development phase.