Reducing emissions from air traffic

Although passengers nowadays fly to their destinations with increasingly small amounts of energy, the growth in air traffic is increasing the consumption of energy and emissions worldwide. There do not appear to be any alternatives on the horizon to using the current fuel, but energy efficiency can be increased by improving aircraft technology or the use of the airspace. The energy efficiency of aeroplanes is improving through current measures by around 1 per cent per year.

Economic measures can also be used to try and direct the development of emissions. These measures include taxes and fees and emissions trading.

The development of aircraft technology

The International Civil Aviation Organization specifies the limits for emissions from aeroplanes. This, together with the rising costs of fuel, is guiding the aeroplane industry to construct aeroplanes that are more efficient and produce fewer emissions.

The consumption of fuel per passenger and per kilometre travelled is approximately 70 per cent more efficient than 40 years ago. Improving energy efficiency will be slower in the future, but several technology development programmes are underway, such as the European ACARE programme (Advisory Council for Aeronautics Research in Europe).

Operational efficiency methods

The consumption of energy and emissions from air traffic can be reduced in other ways, for example, by developing air traffic control procedures and routes so that air traffic flows as flexibly as possible and without delay. Energy efficiency can be increased by optimising the speeds and cruising altitudes of aeroplanes and by flying with the plane as full as possible. The efficient use of airspace and the movement area will reduce unnecessary taxiing, holding and idling of engines in both air and ground traffic.

Domestic flights in Finland use planes powered by turbopropeller engines, which consume much less fuel than jet engines. For example, a full ATR-72 turbopropeller plane flying from Helsinki to Joensuu uses from three to four litres of fuel for one hundred passenger kilometres. Currently, around half of domestic flights are flown with planes powered by turbopropeller engines.

By making the use of airspace more efficient it would be possible to reduce emissions by a few per cent, although this would be a one-off improvement. Eurocontrol, the European Organisation for the Safety of Air Navigation, has developed procedures for assessing emissions from air traffic in various airspace solutions. Further information is available in the links section.

The management of air traffic in Finland is more efficient than in Central Europe because airspace is used flexibly for the needs of both civil and military aviation.

Economic control measures

Various economic means have been proposed to reduce emissions, requiring either a decision at the political level or determination according to market mechanisms. Political solutions would be taxes and fees that would primarily have an impact through reducing demand.

Because of international treaties, the taxation of aviation fuel is generally considered to be almost impossible to implement for international flights. Air traffic is considered of such importance for the economies of countries and movement of citizens that control measures for emissions from domestic air traffic, prescribed at a national level, have hardly been used.

Is emissions trading the solution?

Emissions trading would be an alternative market-determined control method. In theory it would work in just the right way – since costs for reducing emissions in air traffic would rise steeply, air traffic would have the opportunity to buy its allocations from actors in other production sectors. In this instance everyone would benefit.

However, the feasibility of emissions trading has been criticised. Airlines in particular maintain that possible emissions trading must not cause distortions in the competition between companies and that solutions must be implemented at a global level since air traffic is by definition an international business. During 2006, the EU Commission has prepared a proposal for legislation that one way or another would incorporate air traffic within the scope of EU's current emissions trading scheme.