Air New Zealand Ltd.’s decision to ditch its 2030 emissions target suggests more airlines will also have to confront a harsh reality: There’s simply not enough sustainable fuel or new, more-efficient aircraft. 

This double-whammy has left the world’s commercial carriers, among the planet’s biggest polluters, without their two best decarbonization weapons. Global supply of sustainable aviation fuel will be just 0.5% of total fuel requirements this year, according to the International Air Transport Association.

At the same time, Boeing Co. and Airbus SE can’t make jets fast enough. Boeing, under pressure from regulators, has slowed output to improve quality. Airbus is so stretched it’s even turning down orders. So while next-generation jets can consume 15%-20% less fuel, wait times to get them delivered are years long.

It all means airlines like Air New Zealand have to fly older and dirtier planes for longer, while finding it almost impossible to fill them up with clean-burning fuel. The fact that SAF can be several times more expensive than conventional jet fuel doesn’t make it any easier for carriers to hit near-term carbon targets.

Other airlines struggling to buy enough sustainable fuel may have to follow Air New Zealand’s example, said Jack Shepherd, Sydney-based sustainable fuels manager at Blunomy, an energy-transition consulting company.

The fallout from such decisions would extend far beyond the next decade. If more airlines scrap interim emissions goals, fuel suppliers will be even less likely to invest in SAF production, said Shepherd. At worst, aviation’s mid-century goal of carbon neutrality also disappears from reach, he said.

“If we’re not on track in 2030, then the 2050 goal is going to be hard to achieve,” he said. “When the general public is calling for a decarbonized world, it puts pressure on these airlines and their social license to operate.”

The widespread production of SAF has been slowed by high costs, limited feedstock and patchy policy support. Much of the small volumes available are being produced in the US and Europe.

Air New Zealand had wanted to cut carbon intensity by 28.9% by 2030 from a 2019 baseline, and has now begun work on a new near-term target. It still aims to hit net zero by mid-century.

The Auckland-based company may be one of the first airlines to publicly abandon an interim climate goal, but rumblings about whether aviation’s targets can be hit have been getting louder.

Cathay Pacific Airways Ltd. said this month that the enormity of the task had become clear, following talks with about 50 potential suppliers. “We have really witnessed how difficult it is for the SAF industry to take off,” Grace Cheung, Cathay’s general manager of sustainability, said in an interview. 

Last year, Akbar Al Baker, then-chief executive officer of Qatar Airways, said even the industry’s 2050 net zero targets were unattainable.

SAF, made from waste fats or agricultural feedstock, could cut emissions by almost 80% if it fully replaces jet kerosene, according to airlines. They’re betting their sustainable future on SAF because other fuel sources such as hydrogen or electric batteries remain far from commercialization. 

But even with aviation’s commitment to SAF, IATA in June cut its estimates for total SAF production in 2030 after finding that many projects were behind schedule. IATA, which represent more than 300 airlines worldwide, said output had to increase by a factor of 1,000 by 2050. Yet IATA said such a rate of increase sounded almost implausible.

The Science Based Targets initiative, the world’s top arbiter of corporate climate goals, does not include many of the biggest airlines on its list of companies with verified net zero targets. Airlines including Iberia, Japan Airlines and British Airways-owner IAG SA no longer make the cut.

Meanwhile, decarbonizing air travel is becoming an even larger job. Emissions from aviation are forecast to rise 82% by 2050 under BloombergNEF’s base case Economic Transition Scenario, which assumes nations and companies rely on technologies that are currently economic. That would see the industry’s share of global carbon dioxide pollution jump to about 6.7% from around 2.7% today.

When it comes to cutting emissions, it’s time for airlines to acknowledge the limits of what’s possible, according to Emirates President Tim Clark.

“We’ve got to have a grown-up conversation about what is achievable,” Clark said in an interview at the Farnborough Air Show this month. “We shouldn’t give up on it. We should just inject a sanity check.”