Battle of the skies as airlines fight over impact of contrails on the climate

Boeing 767 flight deck [image credit: Continental Airlines]

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This report summary says ‘Vapour trails conundrum resurfaces’. Cloud formation plays an uncertain part in the debate, for example. An experiment using AI found that real time route selection could play a part in reducing the supposed ’emissions’ problem. Proposed financial penalties for airlines are inevitably resisted, but they’re up against net zero climate obsession.
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Airlines are usually rather good at presenting a united face to the world, particularly when it comes to lobbying global policymakers, says The Telegraph.

But a recent move by the EU to clampdown on so-called contrails, the vapour that spews from an aircraft’s jet engines in a thin cloud-like formation, has set carriers at each other’s throats.

The International Air Transport Association (Iata), which counts most of the world’s flag-carriers among its members, has lobbied Brussels to limit the mandatory monitoring of contrails to only flights within the bloc, in an effort to ease the burden of data collection.

But it has stoked the ire of low-cost operators including EasyJet and Ryanair.

The two carriers, which get almost all of their revenue from intra-European services, argue that it would be perverse to ignore contrails produced by long-haul flights when the rule comes in next year.

“Unless the full global scope of monitoring is retained, the science will be incomplete and the places in which contrails are estimated to be most abundant will be excluded,” says David Morgan, chief operating officer at EasyJet.

The clash speaks to concerns that financial penalties or requirements for jets to follow diversionary routes may be focused on those regions where data gathering takes place.

The EU’s CO2 emissions trading scheme is itself confined to flights within the European Economic Area after pushback from overseas carriers.

However, the public row between airlines has distracted from more fundamental questions about just how much contrails affect global temperatures in the first place.

While carriers worldwide have pledged to achieve net zero carbon emissions by 2050, they are far less accepting of potential measures for reducing the production of contrails.

That stance is based partly on a unique property of the vapour trails. While scientists find that they contribute to global warming by aiding the formation of high-altitude clouds that stop heat from escaping the atmosphere, they have other benefits.

Under certain conditions they can equally reflect solar energy back into space, preventing it from reaching the surface and helping to cool the planet.

Iata cites research suggesting that, on average, 14pc of flights leave contrails, of which close to 30pc may have a cooling effect.
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The EU’s stance is particularly important because the bulk of contrails are found in Europe and the US, and along the North Atlantic flyway between them, a “goldilocks zone” where the temperate climate coincides with some of the world’s busiest skies.

The supercooled air pockets that give birth to contrails are generally at too high an altitude in tropical areas and too low at the poles for aircraft to encounter them, while the temperate areas of the southern hemisphere are comparatively lacking in flights.

Full article here.
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Image: Boeing 767 flight deck [credit: Continental Airlines]