A prototype for a new jet engine promises to fly passengers halfway around the world — without burning fossil fuels.

The engine, developed at the Institute of Technological Sciences at Wuhan University, would allow passengers to fly carbon-neutral skies. Researchers say it needs only electricity and the air that swirls around it.

Of course, that air needs to undergo a complex process before it can actually fuel jet propulsion.

As the engineers explain in a research paper published this week in the journal AIP Advances, the engine compresses air and ionizes it with microwaves. The resulting air plasma is what provides the engine's thrust.

"Our results demonstrated that such a jet engine based on microwave air plasma can be a potentially viable alternative to the conventional fossil fuel jet engine," lead researcher and Wuhan University engineer Jau Tang explains in a press release.

There's still a ways to go, however, before we fly carbon-neutral skies. Especially considering engineers only managed to launch a 2.2-pound ball about an inch into the air using the engine — although, they note, that's roughly the proportional equivalent of a normal jet engine.

If the "air plasma" engine proves viable, it could revolutionize an industry badly in need of a technological overhaul. These days, airlines are reeling from a coronavirus pandemic that has grounded all but essential flights in much of the world. But the industry had been in a steady decline long before the outbreak.

The ever-increasing costs of fuel has pushed airlines to develop alternatives like biofuels, a renewable energy source produced from biomass. But an even bigger threat to airlines may be changing public opinion. With a world in climate crisis, air travel is increasingly seen as a carbon-spewing indulgence — so much so that Sweden even has a word for it. The term flygskam, literally translates to "flight shame," and it has become pervasive enough in Europe to have a real impact on the industry's bottom line.

An air plasma engine, on the other hand, could alleviate much of the environmental concern with its promise of a carbon-neutral ride.

"The motivation of our work is to help solve the global warming problems owing to humans' use of fossil fuel combustion engines to power machinery, such as cars and airplanes," Tang explains in the release. "There is no need for fossil fuel with our design, and therefore, there is no carbon emission to cause greenhouse effects and global warming."

No fossil fuels are burned to run this jet engine
Engineers have developed a prototype for an engine that's fueled by microwaved air.