Aviation could face substantial challenges if it’s unable to decarbonize in a timely manner, according to the CEO of Airbus, who added that hydrogen planes represent the “ultimate solution” for the mid and long term.

In an interview with CNBC’s Rosanna Lockwood on Thursday, Guillaume Faury — who was speaking after his firm reported earnings earlier in the day — said aviation would “potentially face significant hurdles if we don’t manage to decarbonize at the right pace.”

The environmental footprint of aviation is significant, with the World Wildlife Fund describing it as “one of the fastest-growing sources of the greenhouse gas emissions driving global climate change.” The WWF also says air travel is “currently the most carbon intensive activity an individual can make.”

Faury laid out a number of areas Airbus was focusing on. These included ensuring planes burned less fuel and emitted less carbon dioxide. In addition, the aircraft the firm was delivering now had a certified capacity for 50% sustainable aviation fuel in their tanks.

“We need to see the SAF industry moving forwards, being developed, being grown to serve airlines and to be able to use that capacity of 50% of SAF,” he said, referring to the sustainable aviation fuel industry. “We’ll go to 100% by the end of the decade.”

The above represented a “very important part of what we’re doing” Faury said. “The next one is looking at the mid-term and long-term future to bring to the market the hydrogen plane because this is really the ultimate solution,” he said, noting that a lot of engineering, research and capital commitments would be required.

In Sept. 2020, Airbus released details of three “hybrid-hydrogen” concept planes, saying they could enter service by the year 2035. The same month saw a hydrogen fuel-cell plane capable of carrying passengers complete its maiden flight.

While there is excitement in some quarters about hydrogen planes and their ability to potentially reduce aviation’s environmental footprint, a considerable amount of work needs to be done to commercialize the technology and roll it out on a large scale.

Speaking to CNBC last October, Ryanair CEO Michael O’Leary appeared cautious when it came to the outlook for new and emerging technologies in the sector.

“I think … we should be honest again,” he said. “Certainly, for the next decade … I don’t think you’re going to see any — there’s no technology out there that’s going to replace … carbon, jet aviation.”

“I don’t see the arrival of … hydrogen fuels, I don’t see the arrival of sustainable fuels, I don’t see the arrival of electric propulsion systems, certainly not before 2030,” he added.

On the sustainable aviation fuel front, Faury’s comments represent the latest addition to a discussion that has become increasingly important in recent years as concerns about sustainability mount.  

Although the European Union Aviation Safety Agency says there’s “not a single internationally agreed definition” of sustainable aviation fuel, the overarching idea is that it can be used to reduce an aircraft’s emissions.

In terms of content, Airbus has previously described sustainable aviation fuels as being “made from renewable raw material.” It said the most common feedstocks “are crops based or used cooking oil and animal fat.”

Last week, the director-general of the International Air Transport Association told CNBC that consumers would be willing to pay the extra costs associated with the uptake of sustainable aviation fuel.

“Sustainable fuels are about twice what you’re paying for … the traditional jet kerosene, so it does represent a significant hike in the airline industry’s cost base,” Willie Walsh said. “And ultimately, consumers will have to pay that, that’s far too much for the industry to bear.”

Long term, they would recognize this was the case. “This is such an important issue. Ultimately, they will be willing to pay,” he added.