The scheme for greenhouse gas emission allowance trading was adopted by the European Union in 2003. It is intended to bring about the achievement of important environmental targets set by the European institutions and to fulfill obligations entered into by the European Union and its Member States since the 1990s within the framework of the United Nations, under the Kyoto Protocol. Directive 2008/101/EC (3) provides that from 1 January 2012, aviation is to be included in this EU emissions trading scheme. The Directive required new standards for calculating emissions based on the entire length of the flight. This would include the time flown over countries not members of the EU and also over the high seas as well. The total calculation to be used for assessments would be based on all the emissions connected with the flight. Ps are opposed to the Directive and argue that the inclusion of international aviation in the Trading Scheme was contrary to international law and to the Chicago Convention on International Civil Aviation, the Kyoto Protocol to the United Nations Framework Convention on Climate Change and the 2007 Air Transport Agreement between the European Community and the USA (Open Skies Agreement). The defendant is the United Kingdom Minister for Energy and Climate Change (D) as the national authority primarily responsible for the implementation of Directive 2008/101. Ps take the view that the inclusion of international aviation in the EU emissions trading scheme is incompatible with a number of principles of customary international law and with various international agreements. Directive 2008/101, by which the EU emissions trading scheme was extended to include aviation, is therefore (they argue) invalid. Ps contend that the European Union is exceeding its powers under international law by not confining its emissions trading scheme to wholly intraEuropean flights and by including within it those sections of international flights that take place over the high seas or over the territory of third countries. They maintain that an emissions trading scheme for international aviation activities should be negotiated and adopted under the auspices of the ICAO; it should not be introduced unilaterally. Ps are of the opinion that the emissions trading scheme amounts to a tax or charge prohibited by international agreements.