food, clothing or even work: in most industrialized countries, commuting accounts for much of the energy used in moving around. Another is to improve the efficiency of the vehicles that are used for transporting people or goods. Airbus, which builds the super-jumbo A380 aircraft, says the industry’s performance on fuel consumption is twice as good as in 1960, and the A380
Compared with ground vehicles, the prospect for replacing kerosene in aircraft engines with low carbon alternatives looks far more diffi cult, from a technological and economic perspective. Potential alternatives must meet high demands: supporting extreme cold, lightweight and low cost (kerosene not being subject to taxation) among others.
Meanwhile engineers and airlines are focussing on improved energy efficiency mainly through better engines, lighter materials, increased capacity and lower fuel consumption (by improving air traffic management and energy-saving fl ying techniques).
To apply market rules and adjust the price of air travel to the impact it generates, making other means of transport more attractive at the same time, is another option for reducing emissions. Although emissions from aviation, just as from shipping, are exempted from the Kyoto Protocol in any country’s emission target, the European Commission has adopted a proposal to include aviation in the EU Emissions Trading Scheme (ETS) from 2011. For the post-Kyoto agreement after 2012, the inclusion of aviation emissions could be one of the political solutions.
In 2006 the Scandinavian airline SAS began testing a new landing approach called Continuous Descent Approach (CDA), where the landing itinerary is known to the crew well enough in advance to let the pilot descend in neutral gear without using the power of the engines until the release of the landing gear. Short-haul jets save an average of 150 kilos of kerosene with this method. SAS has applied
the procedure for 2 000 landing approaches to Stockholm’s Arlanda airport. SAS engineers calculated the potential savings in CO2 emissions would have been more than 50 000 tonnes had all 108 000 landings in the past year been handled in this way. For the time being, CDA is restricted to airports with moderate traffic; improvements in air traffi c control co-ordination are necessary for denser air space. Positive side-effects are improved security as the fl ight routes are known further ahead, and reduced noise pollution. Sweden’s goal is that by 2012 three out of five planes landing in Stockholm should use the CDA method. But further measures will be needed to reach SAS’ target of 20 per cent CO2 reduction by 2020.
uses less than three litres per passenger per 100 kilometres – the figure for a small diesel-engined car. It says the plane’s CO2 emissions are as low as 80g per passenger per kilometre, half the fi gure for an average European car.
This fi gure however does not consider the non-CO2-related climate impact of high altitude fuel combustion which is considered to result in two to four times higher impact than from carbon emissions alone (see page 120).
126 KICK THE HABIT THE CYCLE – REDUCE