Ask your average executive whether his or her industry is doing enough to combat climate change and the response will more often than not be the sort of diagnosis reserved by court physicians for absolute monarchs.

Climate change has come of age. Cool and core. And for those industries that are more easily able to cut carbon emissions by adopting off-the-shelf technologies or through simply adapting products and services, it has become de rigueur to parade green credentials inside the corporate boardroom.

emission forecast

But what of aviation? Historically, aircraft and engine manufacturers have long been committed to driving down the cost of flying, principally under pressure from a cost-obsessed airline clientele.

For many working in the industry, aviation has become the undeserved whipping boy of global warming after having toiled away for years tackling fuel consumption on the back of high oil prices, achieving a respectably steady, albeit incidental, reduction in emissions.

Now in the sights of greenhouse gas regulators, the industrial public enemy number one finds itself answering its critics by pointing out with all the conviction of a condemned felon that other industries are far more heinous emitters of carbon dioxide.

As a relatively small contributor, aviation, even on the basis of the most recent growth forecasts, will still only account for 5% of the total warming effect by 2050 as noted in last year's Stern Review on the Economics of Climate Change.

global man made emissions

Stern also pointed out that aviation faces challenges in delivering radical options for emissions cuts because it is limited by the lack of viable jet fuel alternatives and the absence of easy improvements in engine efficiency.

But the reality is that with annual aviation-related emissions rising at around 5% through the increase in global air travel, the industry faces a moral imperative to contain its growth within globally agreed targets for carbon emissions.

Not only are emissions from air travel increasing significantly in absolute terms, but against a background of emissions reductions from many other sources, their relative rate of increase is even greater, which stands to put air travel at risk of becoming one of the major sources of anthropogenic climate change by 2050.

David Lister, an aviation emissions expert with the International Civil Aviation Organisation (ICAO), says the industry is facing a major challenge in what can be achieved in terms of improvements - both in total and rate.

Citing the authoritative 1999 special report Aviation and the Global Atmosphere by the Intergovernmental Panel on Climate Change, which provided 20-year estimates for potential fuel burn improvements, he says the key question remains whether emissions from aviation, with its continuing high growth rate, will match, outstrip or reduce in comparison with other sectors.

"The report projected that traffic growth would be an annual 5% between 1990 and 2015 and this is the case, despite the terrorist activities and wars since 2000. Additionally, fuel use was projected to increase by 3% per annum, due largely to improved aircraft efficiency. The difference between these rates is a significant 40% improvement."

He also makes the point that even though aircraft technologies - such as the 20% improvement in fuel efficiency offered by the Boeing 787 - may exist as commercially available products, the introduction of improvements are largely dependent on fleet replacement, so assumptions here also become critical. "Even with a 20-year life assumption, only 5% of the fleet would be replaced each year. How rapidly we could expect significant change in overall fleet emissions performance would depend on the actual level of change of the new products," says Lister.


The industry argues, however, that with every significant improvement in performance, many of those significant advances in technologies are continuously fed back into older products essentially as upgrades.

Rolls-Royce president of civil aerospace Mike Terrett provides the example of the continuous feedback of Trent 500, 900 and 1000 technologies retrofitted into the Trent 700 as just one area where the engine manufacturer’s efforts have resulted in a 1.5% fuel burn improvement in an older product.

The commercial logic is clear, says Terrett. "All of this feedback of technology means that with time you will get your assets improved in terms of the quality of that asset, including durability and fuel burn. If you create value it benefits both customer and manufacturer."

But if the industry has a limited ability to make revolutionary leaps, where is the incremental path taking it in technology terms?

Europe – where the environmental debate is raging most fiercely – has its Advisory Council for Aeronautical Research in Europe (ACARE), which in 2001 committed the industry to developing technologies that would cut CO2 by 50% per passenger kilometre, cut NOx by 80% and halve perceived noise levels by 2020 relative to 2000 standards.

Many in the industry regard these as ambitious, albeit achievable, goals. According to Greener By Design, an independent advisory body within the UK’s Royal Aeronautical Society, the ACARE targets for 2020, while "extremely" challenging, are achievable. "The laws of physics do not, in our view, make them unobtainable in due course," it noted in its 2006 report.

Exactly how soon they are achieved, it added, "will depend on the priorities adopted and the funding available for research and technology demonstration over the coming decade". It did however envisage that in the long run, an integrated technological, design and operational approach would enable environmental impact per passenger-kilometre to be reduced faster than air traffic increases.

International impact

Certainly, if ACARE can meet or come close to meeting these goals, effectively pushing the pace of ongoing European technology efforts, they will have a wider impact internationally as airlines naturally expect best technological practice in fuel efficiency to be available across global aerospace manufacturing.

The laws of aeronautical physics aside, the law of politically expedient pronouncements on the need for paradigm change will always retain their siren song appeal.

When International Air Transport Association director general Giovanni Bisignani earlier this month threw down an ambitious challenge for the industry to develop a zero emissions aircraft within 50 years and make solid progress in alternative fuel development, it was greeted with jaw-dropping incredulity within the industry.

“This will not be achieved overnight,” conceded Bisignani. “And nobody has all the answers. We can already see the potential building blocks for a carbon-free future: fuel-cell technology, solar-powered aircraft and fuel from biomass. By working together with a common vision, a green industry is absolutely achievable.”

Bisignani’s vision led one senior industry source to voice the thoughts of many a development engineer sweating over existing ACARE 20-year goals: “Great, that’s all we need. Another bloody stick with which any loony NGO can hit us with.”

The ACARE approach is certainly one with which the European industry is happy to work. “Everything goes through a peer review process with a high level of debate about the process, scale and plotting of the direction.

"It’s not a denial or a refusal to move forward, but it’s a desire to work to achieve real and sustainable achievements in emissions reductions,” says the industry source.

Even so, there are signs that ACARE may be feeling the pressure. Six years on from the launch of its 2020 vision, the council has just established a group that could raise the mission bar yet further and lead to a revision of current objectives as early as 2010.

With a longer-term vision in mind, it has also embarked on an exploration of a blue skies conceptual framework for future air travel and a launch report that is due to be published within weeks promises to both question industrial orthodoxy and inspire in equal measure (see Changing the paradigm: Europe’s future vision, P58).

To address near-term progress, however, ACARE will embark on a lengthy and detailed review of the progress made by the various European Commission-level funded programmes, together with the many European national and industry initiatives.

Allied to that will be a recognition that while it is crucial to build better aircraft and engines, together with optimising the operational framework of air travel, so too is a better under-standing of the impact of aviation on the atmosphere and climate.

As Greener By Design noted in its 2006 report, a lack of a robust understanding of the nature and magnitude of the atmospheric effects of aircraft emissions will continue to impede aircraft designers and policymakers alike.

“Aviation emissions are thought to be a bad contributor to climate change, although we don’t know how bad,” says one senior EC aeronautical research official who outlined the approach ACARE.

“If you want to have sound results on the basis of sound analysis, it takes time. It is not enough to know how much an engine is emitting. The problem is to know how those emissions affect climate change,” the official adds.

At May’s ICAO’s Colloquium on Aviation Emissions in Montreal, where some of the world’s foremost atmospheric scientists gathered, it was clear that the jury remains out on many issues: the precise influence of contrails and aerosols on cirrus cloud formation, the role of NOx in changing ozone and methane concentration as well as the effects of aviation emissions at different atmospheric levels.

While the European aeronautical research community can boast that concerted efforts in the past five years have reduced aviation emissions by 12-18% through validated and demonstrated technologies, it is wary of any rush to undermine the current goals set by ACARE.

Francis Couillard heads environmental affairs at French engine manufacturer Snecma, which invests 20% of its research and technology budget into programmes directly linked with environmental performance.

Francis Couillard heads environmental affairs at French engine manufacturer Snecma, which invests 20% of its research and technology budget into programmes directly linked with environmental performance.

He says results coming through from VITAL, the EC-funded four-year 90.9 million ($121.4 million) R&T programme designed to reduce perceived noise of aircraft engines by 6dB, and CO2 emissions by 7%, are positive midway through the programme.

“We really have to achieve these programme objectives first before we go further towards ACARE targets,” says Couillard.

Many of his counterparts at other engine makers share the same concerns, acknowledging the increasing tempo of political debate over the environment that could leave them facing a serious reorientation in direction and pace of development all for the sake of short-term political expediency.

Even in policy terms, harnessing aviation-related emissions becomes ever more intriguing. The lack of imminent breakthrough technologies has led European regulators to attempt to curb the demand side of aviation through market-based measures that in principle are designed to make passengers pay for the carbon dioxide they help put into the atmosphere.

Emission trading schemes are generally seen as a lesser evil by airlines, as they provide essentially with a cheaper means to secure carbon reductions.

Charges and taxes are regarded as the bluntest instrument to curb demand and the level of airline industry scorn that was heaped on UK finance minister Gordon Brown’s move last February to double air passenger duty at UK airports gives some idea of their popularity.

Unpopular move

Not surprisingly, ICAO has endorsed the trading concept, although Europe’s move to cover all international services flying into Europe from 2012 is unpopular with the USA and developing countries.

Taxes or trading? Either means higher costs and less revenue for airlines. Gary Chase of investment bank Lehman Brothers believes that even through the preferred emission trading mechanism, in the short term the result will be weaker margins and lower profits in a historically low-margin industry with little pricing power.

“In effect, [carbon trading] is similar to the impacts of increased fuel prices in an industry with limited ability to pass along those additional costs in the short run. Over a longer period, slight reductions in service will be needed to offset the higher costs, resulting in less capacity.”

A carbon trading regime also by its very nature increases the transparency of an airline’s relative environmental performance and therefore opens up air transport to far greater scrutiny – and not simply by regulators, but by what has often been overlooked: the travelling public.

Increased transparency and accuracy opens the door to actual consumer-driven choice, and will lead to labelling similar to that already used on many consumer goods, for which Stern argued in his report last year.

It is already happening. This year, Nasdaq-listed TRX launched its Carbon Emissions Model, enabling companies to analyse the carbon footprint of their employees’ business travel. TRX’s Scott Gillespie says:

“On a flight-by-flight basis, the decision to use one airline or another does not have a dramatic impact on CO2 emissions. However, when you look at annual airline sourcing decisions, corporate travel managers can contribute very positively to reduced CO2 emissions.”

At the more fragmented consumer level, UK-based regional airline Flybe is also launching its own eco-label scheme to show the precise environmental impact of individual flights. Flybe, which has invested $2 billion in upgrading its fleet understandably wants to market that investment as a selling point.

While such worthy initiatives may allow a flying public addicted to cheap travel to snack on those complimentary nuts with a clearer conscience, political pressure looks set to dominate crucial aspects of an industry that does not yet have the technological solutions to make flying significantly greener.

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Source: Flight International