Although passengers nowadays fly to their destinations with increasingly small amounts of energy, the increase in air traffic is increasing the consumption of energy and emissions worldwide, unless action is taken. Developing engine technologies, more efficient uses of airspace, low-emission flight methods and financial control measures can help to improve emission efficiency. Renewable fuels and electricity may also play important parts in the future.
The development of emissions is also controlled by financial means, the most important of which is the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) to be deployed globally starting from 1 January 2019.
The development of aircraft technology
The ICAO specifies the limits for emissions from aircraft. This, together with the rising costs of fuel, is guiding the aviation industry to construct aeroplanes that are more efficient and produce lower 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 technological development programmes are underway, such as the Advisory Council for Aeronautics Research in Europe (ACARE).
During the past decade, the energy efficiency of air traffic has improved by more than 1 per cent per year. Renewable fuels offer means to reduce emissions from aircraft. Suitable products already exist and they have also been tested, but their expanded use requires continuous production and cost management.
The use of electric power on commercial aircraft is being developed on several fronts. The first electric light aeroplanes are already in production, and Finland has also acquired one. For example, the large aircraft manufacturer Airbus is actively developing hybrid aircraft. Electric aircraft is expected to be ideal for domestic traffic where distances are only hundreds of kilometres.
More efficient use of airspace
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. The efficient use of airspace and the movement area will reduce unnecessary taxiing, holding and idling of engines in both air and ground traffic.
By making the use of airspace more efficient it would be possible to reduce one-time emissions by a few per cent. Eurocontrol, the European Organisation for the Safety of Air Navigation, has developed procedures for assessing emissions from air traffic in various airspace solutions.
The management of air traffic in Finland is more efficient than in Central Europe because there is no congestion and the airspace is used flexibly for the needs of both civil and military aviation.
Low-emission flight methods
Energy efficiency can be improved by optimising the flight speed and cruising altitude. In continuous descent operations (CDO), an aeroplane descends from the cruising altitude without any horizontal flight phase, which reduces fuel consumption and emissions, as well as noise. Using this method, a narrow-bodied aeroplane can save as much as 100 kg of fuel, reducing CO2 emissions by 320 kg.
Suitable fleet for different routes
Domestic flights in Finland often use planes powered by turbopropeller engines, which consume much less fuel than jet engines. For example, a full ATR-75 turbopropeller plane flying from Helsinki to Joensuu uses from 2–3 litres of fuel per 100 passenger kilometres. Roughly one quarter of all flights to and from Helsinki Airport are carried out using turbopropeller planes.
