A Japanese plane carrier could soon power their aircraft with the help of rabbit poo.
All Nippon Airways (ANA), partnered with LanzaTech, are hoping to introduce the greener fuel choice by 2021.
The new fuel would use recycled emissions, such as from steel plants, which are then converted into ethanol using enzymes found in the poo of rabbits, according to Airline Ratings.
This would then be converted into aviation fuel to be used on commercial flights.
The new sustainable fuel would be combined with the fossil fuel that's currently used on a 50:50 ratio.
With a test run on a delivery flight this autumn, it is hoped the new fuel can be rolled out by 2021.
Akihiko Miura, executive vice president for ANA, said in a statement: "Adopting this advanced fuel will allow us to reduce CO2 emissions and meet the ambitious sustainable development goals that we have set for the airline."
Airlines are constantly trying to find new ways to be more sustainable amid a growing backlash about their contribution to CO2 emissions.
Despite IATA claiming that air travel only accounted for 2 percent of man-made carbon dioxide emissions in 2017, many believe this is higher, with more people estimated to be flying in 2036 than are alive today.
Earlier this year, KLM announced plans for a new 'Flying-V' plane which uses 20 percent less fuel.
Nasa is also working on all-electric planes powered by hydrogen fuel which reacts with oxygen to create energy and steam.
France and the Netherlands are also calling for a price hike on flights with a new tax on European flights.
The proposal claims that airlines face lower taxes than other modes of transport which encourages passengers to fly, which they hope to change with the higher tax.
A Frequent Flyer Levy could also one day be introduced to deter passengers traveling by plane.
This article originally appeared on The Sun.