“Fly the friendly skies” was once a memorable slogan cooked up by United Airlines back in 1965 to invoke a spirit of fun to get people on its airplanes. Of course, the airline was talking about its friendly employees, but decades of increasing air travel have left the skies anything but friendly. And, perhaps providing a bit of foreshadowing, the company moved on from that slogan in the late 1990s.

Noise from loud jet engines and increasing amounts of air pollution and greenhouse gas emissions are casting a pall over that “friendly” transportation.

And it’s getting worse every year. While air travel accounts for only 2.5% of global carbon emissions, according to a September report in The New York Times, there’s a worry that the ever-increasing amount of air travel will triple that amount by 2050 — a United Nations projection.

But the International Council on Clean Transportation says new research on emissions from global air travel shows that segment’s pollution may increase 1.5 times faster than even the U.N. estimate.

In September, Greta Thunberg, a young climate activist from Sweden, made a point about this by eschewing a comfortable flight in the friendly skies and instead sailing on a boat across the Atlantic to New York to give a speech at the U.N. on the need for action on climate change. Both her actions and continued vocal presence earned her TIME magazine’s Person of the Year designation.

Back in November before the holiday flying season began, the Transportation Security Administration put out a helpful press release on tips for getting into those friendly skies, but more importantly said that the Thanksgiving Day holiday would see a record number of travelers jetting from one U.S. airport to another: 26.8 million passengers from Nov. 22 through Dec. 2. And expected it to not let up until after Christmas.

“We expect record breaking travel volume this 2019 holiday season, following our busiest summer ever,” TSA acting deputy administrator Patricia Cogswell said in the release. Those numbers proved to be true.

While the airlines and airplane manufacturers have been working on reducing emissions by making their aircraft more efficient, more and quicker work on the science and engineering of cleaning up air travel — and reducing its noise — is needed. To that end, Sen. Ben Cardin (D-Md.) and Sen. Chris Van Hollen (D-Md.), along with colleagues of theirs, introduced legislation late last year to accelerate research and development on cleaner and quieter aircraft.

The Cleaner and Quieter Airplanes Act, along with companion legislation introduced by their colleagues in the House of Representatives, is meant to boost R&D on “electric aircraft technology,” making that work a government priority under the auspices of NASA.

It’s not as far flung as it sounds. Aircraft manufacturers as well as forward-thinking startups have already been working on fully electric and hybrid systems for smaller planes and shorter flights. While clean propulsion for larger craft is still likely decades in the future, it’s certainly a good idea to turbo-charge that effort now.

“We need to harness American ingenuity and find a new way to support our thriving aviation industry while addressing these concerns,” Cardin said in his office’s press release. “Government-funded research undertaken by NASA in collaboration with industry partners is critical to the development of new technologies and concepts in electric aircraft.”

We likely aren’t going to go back to the days when few took to the skies — back when United Airlines first rolled out that slogan. So, we need to work at reducing that transportation mode’s burden on those friendly skies, for our own sake.