Airlines and governments expecting clarity this week at an aviation regulatory meeting in Montreal to devise a global standard on carbon reductions are likely to run into a smokescreen.
At issue is not the punitive cost of unavoidable airplane emissions, but how to reduce them and whether a unilateral carbon tax is a practical way to achieve the aim. All the world's airplanes account for no more than 3 to 4 per cent of atmospheric despoiling - industry, utilities and ruminants are the main culprits - but the cumulative damage decades later from increased flight frequencies needs to be addressed.
That much is agreed. Aircraft makers are doing their part (and protecting sales) designing fuel-efficient, less pollutive planes. It is the political challenge facing members of the International Civil Aviation Organisation (ICAO) meeting in Canada that is the stumbling block. Europe would be the deal-breaker if ICAO fails to produce an agreement that is equitable.
The European Union is acknowledged as a trend-setter in environmental protection, but a carbon tax it has imposed on airlines is an egregious model of trade protectionism. It also is an extraterritorial act out of sync with the modern world.
It should be scrapped forthwith. But there is scant chance of that happening, to judge from the EU climate commissioner's warning last week about ending up "in a trade situation no one would like to be in". Only if the EU drops its insistence will the way be clear for ICAO members to work out an accord that is acceptable to the aviation industry.
Among the hardest to please are continent-size countries with the most aircraft movements - the United States, China, Russia, India and Brazil. These nations have the muscle to show Europe that others can play the carbon-tax game.
This will lead to a trade war that will cripple struggling airlines and blow economies off course.