Opposition is ratcheting up over Europe's unilateral imposition of its emissions trading scheme to cover international airlines from next year, as the spectre of retaliatory action moves closer to the surface.
The European move is already subject to a legal challenge from US airline body the Air Transport Association, to be heard in the European courts in July, while China is the latest dissenting voice from around the world.
"If there is to be a single one, it should be done by ICAO," says ATA president Nicholas Calio. "It's ill-thought out and its practical implications are very costly in terms of growth and jobs."
IATA is promoting an ICAO-led approach and outgoing director general Giovanni Bisignani was particularly critical of Europe's decision to press ahead, describing it as "a $1.5 billion cash grab that would do nothing to reduce emissions" and adding Europe to IATA's wall of shame.
International Airlines Group chairman Antonio Vazquez says it will disrupt competitiveness. "If you need to make a connection and avoid Europe, you would do it. The [traffic] impact would be significant."
Emirates Airline president Tim Clarkfears a "patchwork quilt of complexity" could result if other regions take their action. "What it will spawn is the equivalent of ETS in Australasia, Asia, the Middle East and other parts of the world." He foresees that in the next six months there will be "a lot of activity on the political level" against what adds another level of complexity to an already "highly complex industry".
Noting countries such as China have said they are not prepared to accept solutions being imposed on it, Association of European Airlines secretary general Ulrich Schulte-Strathaus says this sends a "strong message that needs to be taken seriously" by European regulators. He adds: "This is probably going to help lawyers more than environment."