Clear the air

If the effects of climate change are to be restrained, the aviation industry will have to play a significant role. Currently the sector emits only around 2 per cent of the carbon dioxide responsible for climate change. But at current growth rates, experts forecast it could contribute up to 20 per cent of emissions permitted under global emissions caps planned for 2050.

At the end of September, Willie Walsh, chief executive of British Airways, committed the aviation industry to sweeping emissions cuts. The sector, he said, would cut carbon dioxide emissions to 50 per cent of 2005 levels by 2050, improve fuel efficiency by 1.5 per cent a year until 2020 and achieve carbon-neutral growth thereafter.

Giovanni Bisignani, director-general of the International Air Transport Association, the lobby group, trumpeted the moves as evidence that the aviation sector is now in the vanguard of efforts to reduce energy consumption and address global warming.

For an industry that has been criticised for its sluggish response to climate change, the targets mark a significant change. In 1997, aviation emissions were not included in the Kyoto Protocol – the last major international environmental initiative – and, as a result, the sector has been attacked for evading its responsibilities.

But how the new targets will be met remains a contentious subject. One key distinction is whether the industry finds emissions savings from within or relies on external cuts, buying permits for reductions secured elsewhere in the economy, says Ben Combes, an adviser to the Committee on Climate Change, which advises the UK government.

While Walsh’s proposals rely on offsets, green groups have pressed for governments to reduce demand by increasing taxes. At the very least, they argue, the aviation industry should take care of its own emissions. If it does not, Combes notes, other sectors will have to find even greater cuts – stretching the limits of technology.

Jill Brady, chairman of Sustainable Aviation, a UK industry coalition, says global-emissions trading and aerospace reductions go hand in hand. Because of the extended lead times for airplane technology, initially the sector will have to pay for emissions reductions in other areas. Long term, however, aviation will find its “own solutions”.

In that regard, much can be done. Sustainable Aviation, Iata and other groups have outlined key areas for potential emissions savings. Examples include improved engines and airframes, the use of bio jet fuels, and more efficient operations and air traffic control systems.

Not surprisingly, manufacturers that have invested heavily in a new generation of lightweight composite airplanes, such as the Airbus A380 and the Boeing 787, see technology upgrades through fleet renewal as the easiest solution for the industry. Airbus predicts it will deliver 25,000 aircraft, worth $3,100bn, over the next 20 years.

John Leahy, chief operating officer for customers at Airbus, told journalists recently: “Old airplanes are consuming fuel and polluting at about twice, and sometimes three times, the level of brand new airplanes.”

“One of the best things that could happen would be for people to remove their 25-year-old airplanes and replace them with modern A320s,” he said. “The fact is we could do an awful lot by modernising the fleet quickly.”

The difficulty is that new technology only impacts on a limited proportion of the total fleet, says Ben Caldecott, head of environment and energy at Policy Exchange, a thinktank. Because airplanes are expensive and replaced infrequently, new planes will likely make up only 1 per cent of aircraft kilometres flown in 2020, and only 11 per cent in 2030.

To address the vast legacy fleet, Billy Glover, managing director for environmental strategy at Boeing, says manufacturers have pioneered tools to retrofit old engines and modify existing airframes. For example, Boeing estimates its blended winglets – curved wingtips that reduce drag – can cut fuel use by up to 7 per cent on some models.

Another area for potential savings is in air traffic control, where delays and sub-optimal flight paths lead to fuel wastage and unnecessary emissions. For instance, by introducing smoother descent paths for airplanes, Nats, the UK air traffic control organisation, is committed to a 10 per cent reduction in emissions per flight by 2020.

Large-scale efforts to harmonise and update air traffic control could have similar benefits. The European Commission and industry partners plan to spend approximately €30bn ($44bn) rolling out a unified system by 2025 as part of their Single European Sky initiative. The US has parallel plans for its airspace.

At best, however, those efforts might rein in long-term fuel consumption. But to make significant cuts, Caldecott, with Policy Exchange, argues that airlines will have to change their fuel mix entirely – adopting bio jet fuel technology.

While fossil fuels release carbon trapped for millions of years, advanced bio jet fuels are made from algae and other inedible feedstocks that absorb carbon as they grow on marginal land. As a result, over the course of its manufacture and use, bio jet fuels can contribute towards major reductions in greenhouse gas emissions.

According to Iata, however, a 6 per cent mix of bio jet fuels would create a 5 per cent reduction in carbon emissions by 2020, but would require an investment of $100bn. In addition, politicians have been reluctant to back an approach tarnished by its links with early corn-based biofuels for road transport, which pushed up global food prices.

Still, Boeing’s Glover remains hopeful. Since 2008 his company has sponsored a number of flight trials and the US is expected to certify a 50 per cent bio jet fuel blend in the near future. The next step is to develop a commercially sustainable production model.

“Sustainable biofuels are new, they have huge potential, and it is a way to close the loop,” says Glover. “If we can use fuel from plants that absorb carbon as they grow, that is recycling at its best.”

Of course, self interest is another powerful motive for the industry. For example, biofuels can be produced anywhere in the world and offer an alternative to oil with its volatile prices. “New technologies will reduce our emissions but also our fuel bills,” says Brady of Sustainable Aviation.