The aviation industry is making slow, incremental progress on cutting its carbon footprint, with breakthrough ideas proving elusive
In mid-April, a Qantas plane flew from Sydney to Adelaide, on a journey that proved entirely uneventful: a standard take-off, no delays, a smooth landing. The thing that broke from the norm was in the fuel tanks: jet fuel derived from recycled cooking oil.
Aviation finds itself in the eye of a sustainability storm. Commercial flying is responsible for roughly 2% of global carbon emissions, and rising. In the 1990s alone, US carbon emissions from aviation doubled. If our appetite for flying continues unabated, the sector stands to become responsible for 5-6% of all global greenhouse gas emissions by 2050.
Regulators are piling on the pressure for the industry to act, imposing environmental taxes and finding other ways of making polluters pay. Notably, European airlines were incorporated into the EU emissions trading scheme at the beginning of this year. Calls for a global cap-and-trade scheme continue.
No wonder, then, that airlines, aircraft manufacturers and airport administrators are collectively scrabbling around for a breakthrough idea. But where will it come from?
Biofuel breakthrough?
Step forward biofuels. On paper, a non-fossil-fuel alternative to kerosene presents the perfect answer. The 50:50 blend used by Qantas, for instance, emits 60% less carbon than conventional jet fuel. Other chemistries boast an 80% reduction or more.
Millions of dollars have been poured into aviation biofuels over recent years. All the big players – British Airways, Virgin Atlantic, Lufthansa, Cathy Pacific, Air France-KLM, and others – have feasibility programmes in place.
Recent progress is impressive. “Five years ago, it would have been pushing the realms of reality to think that biofuels would have come this far,” says Tony Council, spokesman for the International Air Transport Association, a leading global aviation industry body.
Biofuels got a major boost in 2011 when certifying body ASTM International approved the use of hydro-treated renewable jet fuel for use in commercial aviation. More than 1,500 biofuel-powered passenger flights have subsequently been clocked.
Biofuels are no panacea, however. At least, not yet. For one, the costs are currently prohibitive. Commercial viability will depend on two main factors, says Inka Pieter, head of CSR and environment strategy at airline KLM: consumer demand must increase and feedstock must become more available.
Fuel quality remains a hurdle too. Airliners are different from cars, which can run on varying qualities of fuel. Biofuels must meet the exacting standards of jet-level kerosene, which not all feedstocks can guarantee.
Last but not least are the political issues now attached to biofuels. Use of crop-based feedstocks has been blamed in the past for pushing up food prices and aggravating land use problems.
Fuel efficiency
Finding feedstocks that can be grown sustainably on a large scale is therefore critical. The WWF-coordinated Roundtable on Sustainable Biofuels, which counts several aviation representatives among its members, marks a promising development in this regard. So too does the Aviation Initiative for Renewable Energy in Germany, which counts Total, Lufthansa, and Boeing among its 29 members.
At present, biofuels are still largely at the feasibility stage. Bringing them into the mainstream will require some assistance from government, both financial (in terms of research and development) and legislative.
“Worldwide regulation to stimulate biofuels is of crucial importance to reach scale,” Pieter says.
Aside from what goes into planes’ fuel tanks, the rate of fuel consumption substantially affects aviation’s environmental footprint. Technological advances have made today’s fleets 70% more fuel efficient than the first commercial jets of the 1960s, says Haldane Dodd, head of communications at the independent, industry-wide Air Transport Action Group.
Each generation of new planes is up to 15% more efficient than the last, he says. And Boeing, for example, has even managed to eke out a fuel saving of about 5% by retrofitting winglets on its 737s and 757s.
Meanwhile, the US aircraft maker has just announced a series of design changes to its 737 Max. The modifications include the extension of the tail cone, the integration of a new, aerodynamic engine and the introduction of fly-by-wire spoilers.
The changes promise to deliver “substantial fuel savings”, says Beverly Wyse, vice-president and general manager of Boeing’s 737 programme. (In 2017, that is, when they come into effect.) That’s welcome, but not the kind of step-change required.
Aircraft manufacturers are not without a few breakthrough ideas, of course. One thought exciting aircraft engineers is the concept of “blended wing body” aircrafts, where the wing essentially is the plane. Just don’t expect to see it flying overhead any time soon. “Within 20 years” is Dodd’s best bet for production.
Back to the future
Biplanes are also exciting interest. Researchers at US universities MIT and Stanford are working on a supersonic model that changes shape at high speeds to reduce drag. The idea is rich in potential, but long in delivery (it’s still only at the computer simulation stage).
One downside of playing too much with the current shape of planes is infrastructure. Airports are built to accommodate existing commercial aircraft. A “plane that doesn’t look like a plane” opens costly questions about airport redesign, warns Iain Watt, principal sustainability adviser at Forum for the Future.
But he welcomes the renewed interest in some quarters in the use of airships. US space agency Nasa, for example, is working with California-based company Aeros to develop a prototype. The Aeros Pelican, which is scheduled for its first test flight this year, is equipped with compressor tanks that can add or remove helium so as to adjust the airship’s altitude when airborne. Freight transportation is especially well suited to this form of slow air travel.
At the opposite end of the spectrum, there’s commercial space travel to consider. Barmy? Richard Branson doesn’t think so. The Virgin Atlantic founder set up Galactic Virgin as long ago as 2004 to realise such a dream. The company has carried out several successful, early-stage test flights over the past 18 months.
As trade (and air traffic) between the US/Europe and Asia-Pacific increases, demand for shorter travel times looks set to rise, too. The costs of sub-orbital travel at present appear prohibitive, however. The sheer energy required to reach the edge of space threatens to be environmentally problematic as well.
New flight plan
Air traffic is a final area that holds out hope for big environmental advances. The more direct that planes can fly, the less fuel they require. Subtler measures such as continuous (rather than “step”) descents and quicker taxiing times can reduce fuel use too.
Changes in air traffic require cooperation, however. In Europe alone, there are more than 30 different entities controlling various pockets of air space. Efforts are being made to bring them altogether under the Single European Sky, but the politics are complex, Dodd says. NextGen is engaged in a similar coordinating attempt in the US.
Asia-Pacific is showing more momentum. The industry-led group Seamless Asian Skies recently kicked off a two-year project to harmonise airspace blocks and improve the use of avionics on board aircraft. The group is due to issue a preliminary report in September 2012.
“Air traffic is set to grow in Asia-Pacific, and they are thinking how they can manage that situation before it becomes a problem,” Dodd says.
Fuel use is at the core of aviation’s environmental struggles. Finding alternatives to carbon-based fossil energy is the most obvious solution. Biofuels aren’t there yet, although with the right incentives and the correct technology they could well be soon.
Until then, the industry must continue to look for gains from improvements in aircraft hardware, infrastructure and air traffic control. Those gains will probably be piecemeal rather than game-changing, but their cumulative impact over time will certainly be felt.
Environmentalists can take heart from one salient fact: fuel comprises almost a third of airlines’ costs, giving them the “perfect incentive” to reduce their use of it.
As IATA’s Tony Council concludes: “Just about everything that is good for [cutting] carbon emissions, is good for [airlines’] bottom line.”
Fast facts
- Aviation produces about 2% of man-made carbon dioxide.
- The aviation industry has committed to improving fleet fuel efficiency by 1.5% per year until 2020, cap net aviation emissions from 2020, and halve aviation CO2 emissions by 2050 compared with 2005.
- Air transport supports 57m jobs and over $2.2tn of global GDP.
- Jet kerosene prices are currently four times higher than the average of the 1990s and early 2000s.
Source: Air Transport Action Group