Travel slump helps clear air as airline emissions drop

Global aviation emissions will fall by 6.5 per cent this year to 623 million tonnes of carbon dioxide as airlines park aeroplanes and reduce flight frequencies because of the economic downturn, the International Air Transport Association (IATA) said. The decline underlines how the downturn has stalled the global economy and offered a brief respite in the steady march upwards in global man-made greenhouse gases emitted into the atmosphere, which could raise global temperatures significantly later this century, according to the Intergovernmental Panel on Climate Change.

Airlines, global air forces and executive jets will reduce their annual contribution by 43 million tonnes this year, accelerating a slight decline registered last year from 671 million tonnes to 666 million tonnes, as carriers began to reduce their operations in line with falling demand. Of this, 31 million tonnes were spared because of capacity cuts, while 12 million tonnes were slashed because of efficiencies such as newer, more fuel efficient aircraft and shorter routes through government concessions regarding airspace flyover rules.

"Airlines are continuing to take delivery of new fuel efficient aircraft and take older less efficient aircraft our of the fleet, despite the recession and credit crunch," said Brian Pearce, the chief economist at IATA. "This improves both fleet fuel [consumption] and carbon dioxide efficiency." Airline engines, like all combustion engines, create as a byproduct carbon dioxide, a greenhouse gas that traps the sun's rays in the atmosphere. In addition, IATA said, nitrogen oxides emitted from aircraft engines also contributed indirectly by creating ozone in the lower atmosphere, although it said little is still known about the effect of contrails on climate change.

The savings in emissions forecast for this year pale in comparison with the overall emissions from all sources, because airlines currently contribute less than 3 per cent of the global total. Global carbon dioxide emissions last year, including from power generation, land transport vehicles, forest fires and industrial plants, rose 1.94 per cent year-on-year to 31.5 billion tonnes, according to the German renewable energy industry institute IWR.

This represents nearly half of the rate of growth of carbon dioxide emissions from 2007, a slowdown due to spiralling oil prices and the financial crisis last year. Emissions rose 41 per cent between 1990 and last year, with the rate of growth rising by an average of nearly four per cent since 2002, according to the Netherlands Environmental Assessment Agency. Although still making up a small piece of the overall pie, the aviation industry is expected to increase in share of emissions to 5 per cent by mid-century, and faces regulation from the EU in 2012 in the form of an emissions trading scheme.

Advances in engine and aircraft design technology have helped the industry to improve its fuel efficiency by 20 per cent over the past 10 years, and IATA has a stated goal of a carbon-neutral airline industry by 2020, meaning total emissions would remain flat even as demand grows. It believes it can achieve this goal through technological advances such as an emissions-free aircraft within 50 years, as well as the use of alternative fuels, solar power and hydrogen fuel cells.

In the Gulf, airlines such as Emirates Airline, Etihad Airways and Qatar Airways have some of the newest fleets on the planet, and the most fuel efficient. However they have elected not to cut capacity and ground aeroplanes during the crisis, and are instead adding new aircraft in a long-term strategy to increase market share. But there have been some moves towards reducing emissions. The state-owned Qatar Airways, seeking to gain an advantage from its country's massive gas reserves, is preparing to trial an alternative aviation fuel derived from natural gas, which burns much cleaner than petroleum-based fuels.

In the UAE, the General Civil Aviation Authority recently concluded an agreement with the Armed Forces that would allow airlines to fly through a special air corridor within military airspace, drastically shortening routes for many flights to southern destinations. [e-mail]