Having pledged to pursue carbon-neutral growth from 2020, airlines are committed to reducing the environmental cost of flying even as they gear up for decades of continued growth in air transport.
A key tool in achieving this is the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)"”a global market-based mechanism that will help airlines to effectively cap net emissions at 2020 levels.
CORSIA is just one component in a basket of long-term measures to meet the industry"™s aspirational 2050 target
For every ton of carbon emitted above the 2020 baseline, airlines will invest in UN-approved carbon-offsets.
CORSIA is just one component in a basket of long-term measures to meet the industry"™s aspirational 2050 target. By that time, the industry aims to reduce its net emissions to half of 2005 levels.
The other three are infrastructural improvements, operational advancements, and technological development, including sustainable aviation fuels, commonly referred to as biofuels.
"A finished sustainable alternative jet fuel still produces the same amount of CO2 (carbon dioxide) as a regular fossil kerosene [when combusted]", explains Robert Boyd, IATA"™s Manager, Environment-Alternative Fuels.
"But the environmental improvement is in the process of producing that fuel.
«If the feedstock is in a plant material, for example, then producing that feedstock involves drawing CO2 out of the atmosphere."
This reduced carbon footprint across the lifecycle of a sustainable fuel means that emissions savings of up to 80% are achievable when compared with the extraction, refinement, and delivery of fossil fuels.
Factor in the myriad of potential sources of biomass feedstock"”ranging from plant crops to forest residuals to municipal waste"”and it is easy to see why sustainable fuels are considered one of the industry"™s best bets for an eco-friendly future.
Immature supple chains
However, in a commercial sense, alternative fuel development remains in its infancy.
Just 4% of global road transport fuel is derived from biomaterial, a figure that falls further in the aviation industry, where stringent safety requirements slow the uptake of experimental technologies.
It"™s about how far we"™ve come in a short space of time. A decade ago we"™d never even had a test flight with alternative fuels
Inevitably, immature supply chains mean that sustainable fuels have lower economies of scale and thus higher costs than fossils fuels.
"The current levels of alternative fuels being used in aviation remain relatively small in absolute terms," admits Michael Gill, Director Aviation Environment at IATA.
"But it"™s about how far we"™ve come in a relatively short space of time. A decade ago we"™d never even had a test flight with alternative fuels.
«And yet here we are today with 5,000 commercial flights having used them, and regular commercial operations on alternative fuels at a number of airports around the world.
"When you compare that with the journey that conventional fuel has taken, we"™ve actually achieved quite a lot in a very short space of time."
IATA has a two-pronged approach to developing the fledgling sector. Advocacy work raises awareness among policymakers and spurs commercial partners "to be ambitious and brave" with their investments.
At the same time, IATA is contributing to ICAO Committee on Aviation Environment Protection (CAEP) working group"”including the Alternative Fuels Task Force, which is establishing universal criteria for sustainability standards deemed eligible under CORSIA.
The latter point is crucial because the first-generation of biofuels attracted criticism for the unforeseen consequences arising from their harvesting.
This included direct environmental harm such as deforestation for crop-growing"”which releases huge volumes of carbon into the environment"”and indirect social harm, such as impacting food security and water supplies.
Alaska Airlines began trialing sustainable fuels on commercial services in 2011
Boyd confirms that robust standards are already taking shape, with all the Sustainable Aviation Fuel Users Group"™s (SAFUG) 28 airline members pledging to only use alternative fuels that comply with the Roundtable for Sustainable Biomaterial (RSB)"”the gold-standard for sustainability criteria.
"The voluntary certification bodies are very good," he says.
"They do a very thorough lifecycle analysis where they really critique strictly what carbon gets used in the production from the very start right through to the finished fuel."
Forest residuals
One prominent member of SAFUG is Alaska Airlines. The Seattle-based carrier began trialing sustainable fuels on commercial services in 2011, using a 20% blend derived from cooking oil on dozens of flights. More trials were operated last summer with an alcohol-to-jet biofuel made from non-edible field corn.
And in November 2016, the company began testing a biofuel derived from forest residual"”the limbs, stumps, and branches left over from timber harvest"”as part of a publicly-funded project led by Washington State University.
Alaska Airlines has also teamed up with Boeing and the Port of Seattle for an infrastructure feasibility study aimed at minimizing transportation and delivery costs.
If you can produce fuel to scale, the economies are going to be much better
The airline acknowledges that its earliest sustainable fuels were six times more expensive per gallon than kerosene. While that pricing gap has narrowed in more recent trials, estimates still put it at between two and three times the cost of conventional fuel.
"There"™s really just not a commercial supply of biofuel," explains Carol Sim, Environmental Affairs Director at Alaska Airlines.
"On the flights that we have done it"™s been batch-scale production"”not commercial production"”which drives higher costs. If you can produce fuel to scale, the economies are going to be much better."
Minimizing transport lines is critical for environmental as well as commercial reasons, so the Boeing project focuses on locally-sourced feedstock from the Pacific North West and drop-in solutions at Seattle Tacoma International Airport.
IATA"™s Gill describes the supply-chain problem as a chicken-and-egg situation: affordable fuel hinges on the availability of pre-existing infrastructure, yet stakeholders are reluctant to invest heavily until they see proof of commercial viability.
Many leaders see the long-term advantage of moving towards the use of alternative fuels
The problem is compounded by high technical-compliance costs and historically low crude oil prices, both of which dampen the short-term financial case for switching to alternative fuels.
"I"™m sure individual airlines factor that into their commercial decisions," Gill acknowledges.
"But many leaders in the industry genuinely see the long-term advantage of moving towards the use of alternative fuels.
«Of course, it"™s not going to happen next year, but I think we are going to see significant uptake within a mid-term perspective."
Clean blends
Experts are also discovering unexpected benefits from biofuels in both the operational and environmental spectrums.
Airlines have found that they can fly farther on the same amount of fuel, for example, thanks to the higher energy density of "cleaner" blends. NASA, meanwhile, has published a report demonstrating that sustainable fuels produce less soot than fossil fuels when burnt on commercial flight"”limiting the formation of aircraft contrails.
If airlines invest smartly, environmental protection can also go hand-in-hand with socio-economic development.
Gill highlights the "ancillary benefit" for communities when municipal waste becomes a feedstock, while Sim raises the prospect of opening shuttered mills for residuals processing.
You can establish some terrific economic benefits for your country when you start to become a producer of fuel"”rather than an importer
With airlines already sold on the idea of sustainable fuels, it is now up to governments around the world to incentivize the sector"™s growth through policy instruments. On that front, too, there is cause for optimism.
"Policymakers are starting to understand a couple of things," concludes Boyd.
"One is that aviation doesn"™t have the same alternatives that the ground transport sector has, like electrification.
«And, secondly, you can establish some terrific economic benefits for your country when you start to become a producer of fuel"”rather than an importer. So, if governments do provide an incentive, they also get a reward."
