Paris Air Show

Air transport must face green challenge head on

 - June 11, 2007, 11:25 AM

Will flying one day be as taboo as smoking is today, at least in most of Europe? Will it become socially unacceptable in the future to travel by air? Experts who see an unprecedented attack on air transport’s environmental footprint are posing these questions, challenging the industry’s growth for the first time in several decades. And growing numbers of people involved in the air transport industry are acknowledging they can no longer hope this issue will simply go away.

The industry has successfully reduced noise problems in the past, but now its greenhouse gas emissions are threatening its future. So while air transport growth has remained undefeated by terrorism, fuel price increases and many international crises since the first Gulf War, it faces potentially its toughest problem yet in the shape of a strengthening political momentum to restrict expansion of air traffic. The industry is increasingly turning to a combination of air traffic management solutions and new technologies, such as alternative fuels, as it bids to prove its green credentials.

“The fuel efficiency of modern aircraft is 3.5 liters per 100 passenger kilometers. The A380 and B787 will be more fuel efficient than a hybrid car. We target another 25 percent improvement in fuel efficiency by 2020,” said Giovanni Bisignani, director general of International Air Transport Association. With this in mind, the industry body has set a target of 10 percent conversion to alternative fuels by 2020.

Nevertheless, since the Kyoto Protocol on climate change was enforced two years ago, the 27-state European Union has initiated an ambitious campaign to reduce by 5.2 percent the total of greenhouse gas emissions by 2012 (compared to the 1990 level).

Commercial aviation is responsible for only around 3 percent of all greenhouse gas emissions caused by human activity. However, if air traffic continues to grow at a pace of 5 percent per year as expected, its total contribution will be multiplied by 2.4 in the next 30 years.

Aviation and Emissions Trading

Therefore, last December, the European Commission proposed including aviation in the EU emissions trading scheme (ETS). If approved by the European Parliament and the European Council, the scheme would become effective as of 2011 for all intra-EU flights and one year later for all flights using EU airports.

While the overall strategy has received backing from the Commission, Council and Parliament, the details of the text still need to be hammered out by EU lawmakers. Contentious issues in the proposal include the Commission’s decision not to include international flights in the scheme until one year after intra-EU flights, and the level of the cap that airlines will be subject to and the system for distributing allowances.

Even if it finally becomes approved by European authorities and accepted by foreign governments, which is not the least of hurdles facing the EU proposal, ETS may not be the end of the story for aviation emissions. The U.S. government has already declared that it is resolutely opposed to having its carriers subjected to the rules and has made it clear that it will fight this initiative at the highest levels.

Nonetheless, the ETS is proclaimed as being part of a comprehensive approach which includes research into cleaner air transport, better ATM arrangements (such as through Eurocontrol’s Single European Sky/Sesar initiative) and the removal of legal barriers to taxing aircraft fuel. Furthermore, Daniel Calleja Crespo, director of air transport at the European Commission, stated the EC would come up with a proposal in 2008 on reducing aircraft emissions of nitrous oxides, which also contribute to global warming.

On the other hand, aircraft manufacturers and operators stress aviation’s relatively small contribution to overall CO2 emissions in Europe and progress made over recent years in cutting CO2 emissions (70 percent over the past 40 years). Airlines and OEMs also stress the need to improve air traffic management, enabling up to 12 percent cuts in emissions from aviation.

Moreover, the noise issue could return to the ICAO agenda, with the Committee on Aviation Environmental Protection set to revise long-established rules for aircraft noise certification.

What Are the Long Term Solutions?
Faced with these strong environmental concerns, the aviation industry needs to find solutions for the longer term.

To diminish gas emissions, alternative solutions, such as the use of bio-fuels, exist. For instance, Virgin Fuels is investigating a derivative of cellulosic butanol as an alternative to traditional jet fuel. Its sister company Virgin Atlantic Airways made a very public declaration of intent when it made the use of biofuels a condition of its recent order for Boeing 787 Dreamliners.

“By developing renewable fuel sources which can be used by other transport modes, we can help contribute to global energy security for the future while reducing emissions from surface transportation,” said Sir Richard Branson, chairman of the Virgin Group.

The use of hydrogen propulsion is another idea promoted without much success so far by a number of companies. The latest is AeroVironment, a U.S. company which has successfully completed test flights in 2005 of a potentially environment-friendly aircraft powered by liquid hydrogen. According to the California-based company, a full tank of hydrogen would keep an unmanned airplane in the air for 24 hours.

The solar-powered plane like the Solar Impulse concept studied by a consortium led by the Belgian company Solvay and Swiss scientists is another option. But such alternative propulsion systems would probably have limited applications, and will not include mass transport over long distances.

To address noise concerns, several ways are being explored, both at the technological and operational levels.

A more radical departure could be the “silent aircraft” concept studied by the University of Cambridge and the Massachusetts Institute of Technology. This initiative aims to develop a conceptual design for an aircraft whose noise would be almost imperceptible outside the perimeter of a daytime urban airport. This requires radically different aircraft and engine designs. Beyond the concept, there are still many technical challenges to be overcome before the silent aircraft could become a reality in the 2030 time frame.

It is also quite clear that the promoters of SST projects will confront serious technical and regulatory challenges before a next-generation Concorde can achieve supersonic overland flights.

The European aerospace industry and the European Commission are strong believers in the “Clean Sky” initiative. Nine major aerospace companies (AgustaWestland, Airbus, Alenia Aeronautica, Dassault Aviation, Eurocopter, Liebherr-Aerospace, Rolls-Royce, Safran and Thales) are committed to establishing the first Aeronautics Joint Technology Initiative to this end.

The Clean Sky JTI is a large technological research program aimed at radically improving the impact of air transport on the environment through technologies and solutions enabling step changes in the reduction of noise, emissions and fuel consumption for future generation aircraft.

Clean Sky will be the largest European aeronautics research project ever. Its total budget is estimated at e1.7 billion ($2.26 billion) and, if the European Parliament and Council of Ministers agree to the proposal, will include financing from the Seventh Research Framework Program.

Operationally Speaking…

Operational improvements can deliver additional environmental benefits at the airport and air traffic control levels.

One area of investigation is to develop and flight-test new approach procedures. This could include an enhanced form of continuous descent approaches which reduce noise and fuel burn by eliminating level segments, keeping aircraft higher and at lower thrust levels for longer than traditional step-down approaches.

Eurocontrol is also looking at implementing noise quotas for growth-constrained airports through the modeling of radar data as part of a program called ENHANCE (European harmonized aircraft noise contour modeling environment). This could result in an aircraft noise market on the model of ETS for CO2.

“Europe has the power to cut 12 percent of aviation CO2 emissions by implementing the Single European Sky. We have 34 air traffic control centers in Europe compared with only one in the U.S. for a similar traffic and land size. This leads to inefficiencies, delays and too much time in the air,” claimed Bisignani.

“Already in Europe, environmental measures in air traffic management are reducing CO2 emissions by more than two million tons, equivalent to one percent per annum,” reported Eurocontrol director general Victor Aguado.

Airspace improvements can deliver tangible environmental benefits. One of the prime examples of this was the implementation of reduced vertical separation minimums in January 2002 giving, through the provision of more fuel-efficient flight profiles and more direct routings, savings of 300,000 tons of fuel and one million tons of carbon emissions every year.

Clearly, air transport stands at a new cornerstone of its evolution, perhaps the more important since the introduction of the jet engine.  

Air Transport Making Progress, Says New Report

The air transport industry may be doing more to reduce its carbon footprint than it is given credit for, according to a new report by independent consultants PMI-Media Ltd. The authors of Aviation growth and global warming have said that aviation is achieving annual savings of just 4 percent in terms of carbon dioxide (CO2) emissions, and it could save another two percent per year in the near term if the industry makes greater use of fuel-saving technology such as winglets and ground power units at airports.

“The UN’s international panel on climate change and other studies which examine the forecast rise in aviation emissions generally accept that the industry will be able to make annual efficiency savings of between one and two percent,” said co-author Rainer Vogel. “But these reports, based largely on aircraft data of a few years ago, do not take full account of the growth in information technology networks in which aircraft now fly.”

The PMI-Media report details ways in which aircraft can now fly dynamic routes to optimize fuel efficiency and match their performance to prevailing weather data, unlike the current fixed airways. The advances in IT will also result in more precise flight briefings (so air crews do not carry unnecessary fuel), better ATM flow control and more efficient approaches to airports, as well as improved maintenance, repair and overhaul techniques.

Along with co-author Philip Butterworth-Hayes, Vogel has taken a holistic view at all the measures and prospective measures available to aviation as it seeks to play its part in arresting global warming. The broad conclusion is that it can achieve much more even before politically driven measures such as emissions trading are taken into account.

More information on the report can be found at    –T.D.