Aircraft are getting cleaner all the time AUGUST 2010. The flight from Shanghai will be landing at Toronto in two hours' time and the cabin crew have switched on dawn. No more rude awakenings from a blast of sunlight as the plastic blinds are yanked up. Over the next 20 minutes light-emitting diodes slowly illuminate the ceiling with a soft blue hue. The large electronically darkened windows also start to brighten. The passengers have probably slept fairly well too. There is less of that dry, wrung-out feeling often associated with long flights because the air in this plane is less arid and the pressure is higher. The carbon offsets for this trip are also lower because the aircraft is using 20% less fuel than other jets and emitting correspondingly less C02. Welcome on board the new Boeing 787 Dreamliner. With half its primary structure, including the fuselage and wings, made from composites, the 787 is much lighter than any metal aircraft of similar size. That not only saves fuel but allows other improvements. For example, the air is nicer to breathe. Airliners have to be pressurised when flying above 10,000 feet because oxygen levels drop dangerously low. At cruising height, usually around 35,000 feet, cabin pressure in most aircraft is kept at the equivalent of around 8,200 feet (about the same as Mexico City) because maintaining a higher pressure in a conventional aircraft might accelerate metal fatigue. To add to passengers' discomfort, the air is kept as dry as possible because moisture causes metal to corrode. But the 787 is pressurized at the equivalent of 6,000 feet and the air can be kept less dry because the composites are stronger than metal and unaffected by moisture. The first 787 is due to enter service next year. With 200-300 seats and a range of over 8,500 miles, it allows airlines to offer long, direct flights that might otherwise have gone to hub airports for connecting services. So Boeing is pursuing the opposite strategy to its rival Airbus, whose enormous new A38OS will be able to carry twice as many people as the 787s, making hub operations even more efficient. "If you fly a big airplane into a hub you have got to fly a lot of little aero planes into that hub to take people to where they want to go," says Scott Carson, the head of Boeing Commercial Aircraft. True, but as Singapore Airlines calculates, three A38OS can also do the work of four Boeing 747s on its busy flights to Heathrow. In fact, both new aircraft will find the markets to which they are best suited. The real battle between Airbus and Boeing is over which market will prove bigger. Every new aircraft improves on the generation before it, thanks to a combination of new engines, better materials and more efficient flight systems and aerodynamics. Individually, those gains are often relatively small. The tiny winglets that now appear on the tip of aircraft wings, for instance, can produce fuel savings of perhaps 3% by improving aerodynamic efficiency. And instead of using the engine to pump air into the cabin mechanically, the 787's engines power electric pumps, offering further fuel savings. These incremental improvements add up. Even a 1% saving can represent hundreds of tonnes of fuel a year for the average airline, and a similar reduction in emissions. Every tonne of fuel burnt by a jet aeroplane produces 3.2 tonnes of carbon dioxide. It takes roughly 80 tonnes of fuel to fly even the least thirsty airliner from London to New York and back again. Depending on the measurement used, aviation is responsible for some 2-3% of total man-made C02 emissions (see chart 5 on the previous page). As air travel grows, this figure is expected to rise rapidly. A report on the economics of climate change by Britain's Sir Nicholas Stern says C02 emissions from aircraft could more than triple by 2050, making flying one of the fastest-growing producers of the greenhouse gas. But the impact of air travel on climate change could be even greater than such figures suggest because of other emissions by aircraft, such as nitrogen oxides (nox), soot and water vapour, which can form condensation trails and cirrus clouds. Scientists disagree about the exact role of some of these other emissions at high altitudes. The Stern report concluded that they might double the warming effects of the C02. Aircraft emissions could be limited by restricting flying. That could be achieved by imposing higher taxes because a large part of the market (mostly leisure) is price-sensitive. Many environmentalists think this will become necessary. A report last year by the Environmental Change Institute at Oxford University predicted that aviation would consume such a large proportion of Britain's carbon-emissions budget that the government would have to curb growth in air travel. It acknowledged the industry's efforts to make aircraft more fuel-efficient, but was skeptical about the scope for future improvements. Many in the industry, however, are convinced that by using more sophisticated technology and more efficient operating procedures they can make air travel a lot cleaner still. Not unreasonably, they also point to the huge economic benefits that airports and airlines bring and that harsher taxation might scupper. Some studies suggest that aviation may account for as much as 8% of global gdp when you allow for tourism, which is possibly the world's biggest industry, and air cargo, which is now responsible for some 40% of inter-regional exports by value. "People don't want to fly less, they want to fly more," says Andreas Hardeman, iata's environment manager. Try trading Because there is often little alternative to flying-and in the immediate future little alternative to jet aircraft fuelled by some form of kerosene