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.
– – –
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.
. . .
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.
– – –
Image: Boeing 767 flight deck [credit: Continental Airlines]
Tallbloke's Talkshop 
Dog ‘n I wer mulling that over this morning around 6am on field walk after the night’s NOT as forecast heavy rain – well a few puddles survived … with Pollen Tidal marks. Climate-change-be-damned – all those extra trees making for so much more pollen, Dust particles promoting / seeding rain.
So, Contrails ? Puh! More like someone’s entrails been far flung Mile High club ?
Yet, the climerati are ok with cloud seeding!
Contrary to what it says in the Telegraph article, contrails can often be avoided in advance by relatively modest changes to routes, and by reference to weather reports, but airlines are reluctant to apply these changes because they generally involve using more fuel (and I am guessing more carbon tax). Contrail formation is fairly predictable. SAF generates less particulate residues when burnt and thus is expected to produce less contrails as well as emitting less CO2. I think it no coincidence that American airline operators are currently levying for tax breaks on very expensive SAF produced from corn.
It is also puzzling why there has been an apparent uptick in the formation of persistent spreading contrails recently, fuelling the mad ‘chemtrail’ conspiracies online. The question is: Is this because of recent weather changes in the North Atlantic temperate zone and maybe the expansion of the ice supersaturated zone or is it because the airlines are now not bothering to take contrail avoidance measures?
There’s a link to the AI angle in the intro.
In our featured article The Telegraph says:
The problem with relying on SAF to resolve the contrails issue, however, is its poor availability and high price. It makes up only about 0.2pc of the global jet fuel mix, and while IATA says that should rise to 0.5pc this year, the fuel will add a projected $2.4bn (£1.9bn) to costs.
Looks like a dead end apart from a few Branson-type publicity stunts.
I am so overdosed on the Klimate Klowns and their climate hoax.