The fast-growing airline industry has been criticised by environmentalists. Photo / Reuters

The fast-growing airline industry has been criticised by environmentalists. Photo / Reuters

Controversy over aircraft emissions has escalated over recent weeks, with disagreement between the European Union (EU) and most of the world's airlines.

Closer to home, competition has emerged between airlines pursuing alternative fuel solutions, although it appears to be a David and Goliath contest.

On Monday, Sir Richard Branson told a conference in Boston that "early next year" Virgin Atlantic would be conducting a Boeing 747 test flight with one of the renewable fuels his Virgin Group had developed. Noting Air New Zealand's plans for a similar 747 test flight late next year, a Reuters report said "Virgin is trying to beat that airline by testing biofuels first".

The Air NZ initiative was announced on September 28, when the airline signed a memorandum of understanding with its biofuel test partners, Boeing and Rolls-Royce. Virgin's similar agreement is with Boeing and the other major engine manufacturer, General Electric.

Branson has not given more details, but he pledged last year that over the next decade he would spend the profit from his stake in Virgin airline and rail businesses on fighting global warming.

He also created Virgin Fuels, which is investing US$400 million ($533 million) over three years in renewable energy initiatives. Emission reduction aside, this could be a rewarding investment, eventually creating a new fuel giant.

Branson's deal with Boeing, however, also has to be seen in the context of Virgin Atlantic's fleet; two-thirds of which are Airbus planes, with six A380s still to come. Airbus' position on the alternative fuel issue is not known.

Meanwhile, Air NZ is pushing ahead with its campaign not only to reduce the emissions from its aircraft and the company's overall carbon footprint, but to ensure that passengers on its long-haul routes are made aware of the airline's efforts. Following on from a booklet published this year, Air NZ has produced an in-flight video outlining its moves to counter global warming, from aircraft fuel-saving measures to environment-friendly practices at its new headquarters.

Although the international aviation industry's claim that airlines are responsible for only 2 per cent of global carbon dioxide emissions has not been seriously challenged, some critics maintain the impact is greater than that figure suggests. The industry's exponential growth has attracted critical attention, especially in Europe and in respect of low-cost airlines.

The prominent British low-cost carrier Easyjet, has responded to what it sees as distortions about aviation's contribution to the greenhouse gas problem and a lack of credit for efficiency gains that have been made, including those arising from new, fuel-efficient aircraft operated by it and other low-cost airlines.