• Reconfiguration of the airspace - FAB
• Toward the future: A-SMGCS and CDM
• Air Traffic Management - ATM

Three means have been identified:

• Technical progress: Despite an impressive technological development, progress in this field does not compensate for the effects of growth in the sector.
• Economic measures: Among the economic measures considered to stimulate the reduction of emissions, the most promising one consists in the European Union emission trading scheme applied to air transport. Other measures such as the voluntary renewal of fleet through the introduction of more fuel saving aircraft contribute to a decrease in emissions.
• Improvement of procedures: A better airspace management has been identified as a means of reduction of 6 to 12% of the en route emissions, in particular thanks to the use of more direct routes and to infrastructure improvement.

• Eurocontrol has identified that the introduction of six additional flight levels in January 2002 (RVSM - Reduced Vertical Separation Minima) decreased CO2 emissions by one million tonnes, or the equivalent of three whole days’ worth of air traffic in Europe.
• The restructuring of our airspace introduced the concept of flexible sectorisation, and a closer collaboration with our military colleagues allowed to implement level 3 of the Flexible Use of Airspace (FUA). These two measures entailed a decrease in delays, and as a consequence shorter flight durations with a corresponding decrease in fuel consumption and CO2 emission. Thanks to these measures, an A320 can for instance save the equivalent of a tank of car gas, just by making a shortcut of only 8 nautical miles (15 km). The implementation of Flexible Use of Airspace in Europe allows an additional reduction of 400,000 tonnes every year. In 2005 alone, this efficient management of air traffic flows allowed a 1.1 million ton decrease of CO2 emissions caused by air transport.
• The collaboration with the Eurocontrol Central Flow Management Unit (CFMU) also helps to reduce greenhouse gas emissions by introducing more direct flight routes whenever possible and by keeping aircraft on the ground with the engine cut off until there is a slot available, rather than having them taking off and consuming fuel unnecessarily.
• At Brussels Airport, the introduction of CDM (Collaborative Decision Making) limited emission thanks to a better management of ground movements. Case in point: the average duration of ground movements decreased by three minutes, which corresponds to an economy of 17,022 tonnes of CO2 in 2008 compared to 2007.
• Belgocontrol helps defining the Functional Airspace Blocks (FAB) as planned by the Single European Sky, at which the airspace will be managed in function of traffic flows instead of national borders. Belgium and Belgocontrol take part in the creation of the FABEC, together with Germany, France, Switzerland, the Netherlands and Luxembourg. As regards the environment, FABEC strives for a decrease in CO2 emission by an average of 226 kg per flight and in nitrogen oxides by 0.7 kg per flight.
• Even more recent, Belgocontrol, in co-operation with Eurocontrol, the airports and the airline companies, studies the application of the CDA procedure (Continuous Descent Approach) which leads to a significant decrease in emissions and noise in the approach phase, when an aircraft can descend without levelling off during its landing phase. Although this procedure cannot always be applied in a complex airspace with dense traffic, the goal is to raise as much as possible the percentage of flights performing a CDA at times when traffic is low. An optimisation of this procedure is currently being tested for Brussels Airport, in active co-operation with Brussels Airport Company and numerous airline companies.