Environment : A Lifelong Commitment

March 10-12. The International Scientific Conference on Climate Change, Copenhagen. Warnings emanating from the three-day gathering of some of the world’s top climate change experts could not have been starker. Forget the worst case predictions voiced as little as two or three years ago—all estimates have just been revised upward. Emissions are growing faster than what most scientists had forecast, the absorption capacity of the planet seems less than earlier hoped, the probability of high temperatures is now higher than conjectured and some of the predicted adverse effects are becoming visible sooner than feared. In short, the world appears to be on the brink of a dangerous climate change, which could well be abrupt and irreversible. Sceptics may rail against such gloomy projections as lacking adequate scientific underpinning, but their number is dwindling by the day. More people than ever are convinced that immediate and determined action is needed to avert climate change.

The current temporary financial downturn notwithstanding, commercial aviation is growing at a pace faster than technological and operational improvements towards better environmental performance can cope with. Over the past few years, the number of planes crowding the sky has increased manifold even as an increasing number of passengers take to flying. Aviation’s carbon footprint—the sum total of its carbon dioxide (CO₂) emissions—is steadily expanding, landing the industry in a quandary: how to continue to expand responsibly while further reducing impact on the global ecosystem?

Surprisingly, aviation related greenhouse gas (GHG) emissions were not included in the original Kyoto Protocol commitments and are not currently subject to any international climate change treaty. The reason for this glaring omission is that flights operate across international borders, making it hard to pinpoint responsibility for emissions. The International Civil Aviation Organisation (ICAO) is at the receiving end for not acting swiftly and decisively to arrive at a workable solution to this problem and mitigate the impact of aviation on climate change.

Life Cycle Approach to Emissions
Aviation GHG emissions are mainly the result of fuel burnt in flight. Each litre of fossil fuel saved translates to reduction in emission of 3.2 litres of CO₂. Currently, there are very few low-carbon solutions for reducing aviation emissions, and alternative fuels may be the only option for large-scale application. Nevertheless, any decision on alternative fuels needs to take into account total life cycle costs and carbon footprint. Scientists say deforestation accounts for a fifth of global GHG emissions, while aviation contributes just 2 to 4 per cent. Why, then, did some governments over the last few years set mandatory biofuel targets even as they ignored the decimation of carbon-absorbing forests and the resultant soaring food prices?

The need of the hour is to develop sustainable, plant-based fuel sources that offer a carbon footprint lower than that of fossil fuel and do not compete with food, land and water resources. Such second and third generation biofuels absorb CO₂ when growing and, consequently, could offer up to 60 per cent CO₂ reduction over fossil fuel in the course of their life cycle. A key requirement is that alternative fuels should be drop-in, that is, readily useable without any modifications to the existing jet engines. These also need to be easily available and cost competitive.

While the International Air Transport Association (IATA) is committed to using 10 per cent alternative fuels by 2017, there are signs that relatively low international oil prices, coupled with the current economic downturn, are deterring investment in the development of alternatives. A recent opinion poll by the Association of Corporate Travel Executives concluded that green forms of business travel are suffering due to recession, as organisations prioritise cost-saving over sustainable travel. According to the survey, companies consider cost-cutting to be the top business travel concern (rated a high priority by 79 per cent of respondents) while environmentally sustainable travel is important to only 17 per cent.

Airframes & Engines
To a large extent, making aviation greener depends on reducing aircraft GHG emissions. However, it would be wrong to ignore the environmental impact of aviation as a whole. A life cycle approach begins with manufacturers who need to constantly find ways to improve their aircraft, including the environmental impact from design to production to operation to dismantling. This is no different from any other major industry. Airbus is the first airliner manufacturer to have certified to international environmental standards ISO 14001, for full life cycle coverage, including all products and manufacturing plants. For industrial and manufacturing operations, by 2020, Airbus is targeting at least a 30 per cent reduction in energy consumption and 50 per cent reduction in CO₂ emissions, despite the growth expected. Its environmental responsibility charter also includes optimising water consumption and minimising all waste. Boeing’s aim for the 787 Dreamliner programme is that the aircraft should have far less adverse impact on the environment than the types it replaces.

Airframe manufacturers’ green dreams depend largely on lightweight composites—materials made of several components, including carbon fibres. These are strong and flexible as metal, but as light as plastic. Half the weight of aluminium and a fifth that of steel, use of a typical composite cuts weight and decreases fuel burn, thereby reducing carbon emissions. The Airbus A380 is around 30 per cent composite, while the future Airbus A350 and Boeing’s 787 will be more than 50 per cent composite: a tremendous saving in weight, fuel and carbon. However, the picture may not be all rosy—much of the weight could be back when other essential properties are factored in, such as lightning strike protection, earthing, flame resistance, noise damping and impact resistance.

Upgraded engines play a major part in reducing fuel-burn, emissions and noise. Manufacturers around the world are spending huge sums of money striving to make their engines more fuel efficient, cheaper to operate and more environment-friendly. Historically, however, the fuel efficiency of jet engines has been improving annually at just 1 to 2 per cent. Obviously, even this cannot continue indefinitely. Further progress requires increasingly advanced technologies in the fields of aerodynamics, structures, systems, propulsion systems and aircraft configurations. Even if manufacturers have so far been able to simultaneously reduce noise and fuel-burn, a point is now being reached where trade-off decisions involving emissions and noise, and even among varying types of emissions, could begin to appear. IATA has set a goal of creating a zero-emissions airplane within 50 years. Achievable target or just wishful thinking? Time will tell.