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Etihad’s ‘Greenliner’ exhibits a glimpse of a extra sustainable future for aviation

(CNN) Whereas some delegates finally week’s COP27 local weather convention have been criticized for arriving by personal jet, others arrived in Egypt aboard flights that have been described as being emission-free, as they have been powered totally by sustainable aviation gas.

The flights have been a part of a program referred to as “Greenliner,” run by Etihad Airways, the nationwide provider of the United Arab Emirates, as a testbed for sustainable air journey options.

Business aviation accounted for simply over 2% of world CO2 emissions in 2021, which suggests it might be a modest contributor to local weather change. However the quantity would not inform the entire story, as air journey impacts the local weather in additional complicated methods than simply carbon emissions, and its impression is predicted to rise sooner or later, as an increasing number of individuals will wish to fly.
Whereas renewable vitality and electrical autos supply clear pathways to decarbonize sectors like energy and highway transport, it is much less straight ahead for the aviation business.
Consequently, the business isn’t on observe to satisfy its internet zero goal by 2050, and is banking on two thirds of that transition coming from sustainable aviation gas (SAF). It is produced from waste merchandise and may curb emissions by 80% on common — however it at the moment accounts for simply 1% of world jet gas utilization. One thing wants to vary, quick.

That is why SAF is among the key components of the “Greenliner” program. “It is basically a name to motion,” says Mariam AlQubaisi, head of sustainability at Etihad. “The thought happened in late 2019 to launch a message to the business: let’s strive all the pieces potential to decarbonize.” This system relies across the Boeing 787 Dreamliner, however Etihad has an identical initiative, referred to as Sustainable50, devoted to the Airbus A350. Since its launch, Greenliner has championed the adoption of SAF and tackled points corresponding to plastic waste and inefficient flight routes.

Ethiad’s “Sustainable50” Airbus A350.


The “Greenliner” moniker is usually used to confer with a selected 787 plane, which AlQubaisi calls this system’s “mascot.” Unsurprisingly, it is painted inexperienced — which she says is a solution to pre-empt accusations of greenwashing.

“Any challenge any airline would launch will all the time be scrutinized underneath the umbrella of greenwashing,” she explains. “Portray the plane inexperienced was a solution to problem that and say it’s devoted to a function. We’re proudly owning as much as our emissions: We’re saying sure, we’re a significant emitter — however we’re doing one thing about it .”

A fast repair

Etihad ferried delegates to Sharm El Sheikh in Egypt, the place COP27 happened, by including a stopover to its common Washington Dulles to Abu Dhabi service. The flight was described as “emission-free” resulting from being powered fully by SAF — however confusingly, the planes truly used conventional jet gas.

The obvious absurdity highlights challenges with each SAF infrastructure and speaking inexperienced initiatives. The airplane did not have SAF on board as a result of present rules prohibit business flights from utilizing greater than 50% SAF, as not all engines are licensed for increased concentrations. Plus, not all airports have the infrastructure to make use of it, and the inexperienced gas should come from a manufacturing facility comparatively near the airport to keep away from canceling out the discount in flight emissions with these coming from transportation.

So, Etihad bought sufficient SAF to energy the flight and delivered the gas to Los Angeles Worldwide Airport, which has the required infrastructure and services. There, the SAF was built-in into the airport’s refueling system with conventional gas, and utilized by whichever plane have been refueling that day. This method is named “E-book & Declare,” and it is at the moment the one approach for a flight to assert it is utilizing 100% SAF. The emissions are merely offset elsewhere, relatively than on one particular flight.


Etihad’s “Greenliner” program exams out sustainable initiatives on this Boeing 787 Dreamliner.


AlQubaisi calls it a “fast repair” till rules change, however for SAF to turn into extra widespread, extra progress is required. “The worth of SAF is 4 to 5 occasions that of standard jet gas and it is restricted in provide. Solely two our bodies are allowed to certify it, so till we have now extra and till governments intervene to incentivize manufacturing, SAF will proceed to be restricted, she says.

Etihad has used SAF extensively in a collection of “EcoFlights,” which make use of the provider’s 787 and A350 fleet to evaluate new sustainability initiatives. These culminated within the airline’s most environmentally pleasant flight ever, a London Heathrow to Abu Dhabi service on October 23, 2021. The flight, Etihad says, achieved a 72% general discount in emissions through the use of 38% SAF (by way of ‘E-book & Declare’ ‘) and adopted a bunch of different measures, corresponding to lowering single-use plastic by 80% and delivering baggage by way of electrical tractors.

It was additionally the primary business flight to check a novel solution to fight emissions, through the use of navigation and synthetic intelligence to keep away from the formation of contrails. These are vapor trails that kind when ice crystals coalesce across the exhaust gases emitted by plane engines, and end in momentary clouds that entice warmth, contributing considerably to the warming impact of air journey. However modifying the airplane’s route or altitude will help dramatically. “The warming you are avoiding by merely including a little bit extra time to the journey is as much as 60%, if no more,” says AlQubaisi. “What’s good about that is that it is performed by way of particular algorithms that make the system turn into smarter the extra we use it.”

A greener future?

Etihad’s “EcoFlights” have trialed a variety of applied sciences and methods geared toward lowering emissions, corresponding to an optimized climb and a steady descent, last-minute engine start-up, taxi procedures utilizing a single engine, and washing the engine with a particular foam that improves effectivity by lowering the build-up of deposits.


Good navigation will help to cut back a single flight’s carbon footprint.


Many of those methods have since made it into on a regular basis operations, and in recognition of those efforts Etihad was named “Environmental Airline of the 12 months 2022” on the annual Airline Rankings awards. In accordance with Geoffrey Thomas, Airline Rankings’ editor-in-chief, Etihad has proven “clear management within the push for sustainable flight.”

There’s nonetheless lots to be performed, AlQubaisi says: “That is an business that has had free rein on air pollution for a few years and it is about time we come clean with our accountability to decarbonize.”

The important thing to attaining a greener aviation is everybody working in direction of it, she provides: “Hopefully you may hear of extra airways becoming a member of the Greener program, as a result of it would not matter who does it first — what issues is who does it higher.

“We are able to do higher collectively, as a result of sustainability isn’t an space for competitors, it is an space for collaboration.”


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