Environmentalists out to restrict air travel growth in order to combat global warming will have taken heart from the recent report by eminent British economist Sir Nicholas Stern on the Economics of Climate Change. In his 600-page document, prepared for the UK Treasury, Stern makes clear his conclusion that ‘business as usual’ is not an option and that humanity must change its energy behaviour. It seems unlikely that aviation, as a high-profile emitter of greenhouse gases, can escape this process. This will have implications for reinforced plastics.

Stern has made economic projections based on the growing scientific consensus that the global climate is changing and that humankind is a substantial cause. While accepting that his work piles economic uncertainty upon scientific uncertainty, he argues that levels of carbon dioxide (CO2) in the atmosphere must be kept below 450-500 parts per million (ppm) if a rise in average global temperature is to be limited to 2°C – itself a potentially critical increase. But levels of this greenhouse gas, which lingers in the atmosphere for up to a century, are already at 430 ppm and rising at some 2 ppm per year.

Aviation, with its high use of fossil fuel, has attracted environmental opposition, though its effects are often exaggerated. Authoritative sources point out that air transport accounts for 3% of man-made CO2 emissions, rather less than is popularly supposed. According to Mike Ambrose, director general of the European Regions Airlines Association, even this figure is an exaggeration, an official document released without fanfare on the European Union's website reporting the true figure as being nearer 1.5% – half that usually quoted. Moreover, aviation is constantly improving its energy efficiency, thanks in part to composites. A new breed of ‘plastic’ transports – notably the Boeing B787 and Airbus A350 – will take this process further. Improvements in air traffic management can reduce unecessary miles flown.

Unfortunately, though, aviation is a victim of its own success. Having made flying affordable for millions more people with new business models and technology, it finds that its consequent growth has placed it firmly in the environmental firing line. Arguments from low fare carriers that their planes are new and fly full, so that their per-passenger emissions are low, fall on deaf ears. Neither are critics impressed by claims from legacy carriers like British Airways, which says it has increased its fuel efficiency by a quarter since 1990 and cut CO2 emissions by 15%. Aviation will probably have to take a hit, in the form of increased taxes, or by having to buy credits under carbon trading schemes.

The UK government, for one, wants aviation across Europe to be brought into the European carbon trading scheme by 2008. Ultimately, measures taken will have to be international, and preferably global so that airlines compete on a level playing field. The International Civil Aviation Organisation (ICAO) would be a suitable coordinating body.

Sir Nicholas' conclusion that a 1% of gross domestic product (GDP) spend now on climate change mitigation could avert a 20% GDP hit (ie. a major depression) in years to come, will strengthen the mood for squeezing fossil fuels. Aviation's boom times, following the severe dip that followed the September 11th attacks, are therefore under threat. The fall-out for reinforced plastics might just be positive, with composites gaining ground as their weight saving properties continue to enhance fuel efficiency. Industry executives caution, however, that if aviation growth is severely curtailed, fewer aircraft will be ordered and the outcome for composites could just as easily be negative.