(Bloomberg) --

Ryanair Holdings Plc Chief Executive Officer Michael O’Leary rekindled a war of words with the discount carrier’s full-service rivals, saying the single biggest step people can take to cut carbon emissions is to stop flying with British Airways, Deutsche Lufthansa AG and their peers.

“Everyone who switches to Ryanair from one of Europe’s legacy airlines, the old tax-exempt, polluting BA, Lufthansa, Air France, is reducing their environmental footprint by about 50% on intra-EU air travel,” O’Leary said at the Eurocontrol aviation sustainability summit in Brussels on Monday.

O’Leary also lambasted at the International Air Transport Association, whose membership excludes most low-cost airlines, saying that the virtues of the fuel-efficient planes used by most discounters is “a message you won’t hear” from the trade group. “We know our position here is to sit behind IATA and be lectured.”

IATA Director General Willie Walsh, the former head of BA parent IAG SA, dismissed O’Leary’s comments, recalling in a retort laced with an expletive that the Ryanair CEO had once said airline industry leaders were prone to hyperbole. 

The dust-up marks a return to the heated exchanges that flared in 2019 before the coronavirus pandemic grounded flights. Back then, Ryanair argued that the long-haul services and premiums cabins offered by the likes of Lufthansa were hugely inefficient compared with its own new, densely packed planes. Lufthansa CEO Carsten Spohr hit back by saying bargain-basement fares were “economically, ecologically and politically irresponsible,” stoking demand for needless travel and making the industry an easy target for climate campaigners.

Monday’s encounter serves as a reminder that those divisions remain, even as the industry seeks to present a united front addressing growing pressure to decarbonize. The industry is already facing a rise in virus infections that threatens to unwind a modest rebound in flying. 

While IATA members have endorsed a commitment to reach net zero emissions by 2050, Eurocontrol Director General Eamonn Brennan opened the conference by declaring that the industry has already “lost the PR battle” on carbon and that “environmental activism is taking over.” He said the public perception is that aviation accounts for more than 20% of global emissions, when the real figure is under 3%.

At the event, O’Leary said long-haul operations should no longer be excluded from the European Union’s carbon market rules since those flights produce the most pollution. He suggested the exemption is no more than a means of protecting flag-carriers from international competition.

“All we’re taxing is European citizens on their intra-EU air travel while we exempt the Chinese, Americans, the Russians and the Asians,” he said.

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