After struggling through the global pandemic, air travel is set for a rebound — and that is stoking concerns about the climate.Aviation's environmental footprint is significant. It's considered one of the fast-growing sources of greenhouse gas emissions on the planet.That is why the airline industry has committed to net-zero emissions by 2050 — but it won't be easy."2050 seems like a long way away," said Sharon Pinkerton with Airlines for America. "But if we're going to meet our targets, then we're going to have to have both speed and scale."New sustainable fuels and more efficient aircraft are on the horizon — and some solutions are already taking off.The innovators of the world are creating new hydrogen, electric and solar-powered airplanes."It has to be able to be dropped into the system, and it has to be safe," Pinkerton said. Boeing has pledged to develop the world's first zero-emission commercial aircraft by 2035 using hydrogen propulsion. United Airlines is planning to purchase 100 hydrogen engines by 2028 from a company called Zero Avia. Aviation contributes just over 2% to global carbon dioxide emissions, and experts say that amount could triple by 2050 if action isn't taken.Watch the video above to learn more.