In a landmark decision, on December 21, 2011, the Court of Justice upheld the extension to international aviation activities of the greenhouse gas emissions trading scheme (ETS) of the European Union (Union or EU) against a challenge that it violates several treaties and principles of customary international law. In addition to its broader significance in the context of global versus unilateral approaches to tackling climate change, and its related role in fueling a major international trade dispute, the ruling pronounces on important aspects of international aviation law and clarifies the principles governing conformity of EU internal legislation with international law.
