The ECJ Judgment on the Extensions of the ETS to Aviation: An Economist's Discontent
Few EU decisions have caused more international outcry than the extension of the EU Emissions Trading System (ETS) to apply to aviation. The directive was legally challenged by US airlines before a UK court, which referred the case to the European Court of Justice (ECJ) for a preliminary ruling concerning the compatibility of the directive with international law. This paper discusses the argumentation by the ECJ and the Advocate General from an economic perspective. Such an analysis is warranted in light of the fact that the contested measure is an economic regulation, the international laws that are invoked have clear economic objectives, and the ECJ judgment and the opinion by the Advocate General at least partly rely on economic concepts and mechanisms. An economic analysis also seems warranted from a legal point of view since the quality of the judgment and of the opinion presumably depend on the soundness of their economic reasoning. It is found that the argumentation by the legal authorities is highly questionable in important parts, when viewed from an economic perspective.
The Triumph of Politics: Reflections on the Judgment of the Court of Justice of the European Union Validating the Inclusion of Non-EU Airlines in the Emissions Trading Scheme
The planned extension of the European Union emissions trading scheme to non-EU carriers has provoked vociferous opposition and prompted debate among scholars and practitioners of international and environmental law. US airlines challenged the relevant EU directive in the English High Court, arguing that it is incompatible with international law. The High Court made a preliminary reference to the Court of Justice of the European Union. Advocate General Juliane Kokott provided an advisory opinion in October 2011 that upheld the validity of the directive. On 21 December 2011, the Court issued a judgment that largely adopts the Advocate General's reasoning. The article contends that the Advocate General and the Court, in their juristic pronouncements regarding the novel legal issues in this case, exalt political concerns over adherence to traditional understandings of fundamental principles of international aviation law, notably sovereignty, extraterritoriality, and the applicability of the Chicago Convention. The authors conclude that the integrity of the international aviation system depends on levels of international cooperation that are inconsistent with the unilateralist, interest-driven readings of legal principle evident in both the opinion and the judgment.
Aerodynamic Contrails: Phenomenology and Flow Physics
Aerodynamic contrails have been recognized for a long time although they appear sporadically. Usually one observes them under humid conditions near the ground, where they are short-lived phenomena. Aerodynamic contrails appear also at cruise levels where they may persist when the ambient atmosphere is icesupersaturated. The present paper presents a theoretical investigation of aerodynamic contrails in the upper troposphere. The required flow physics are explained and applied to a case study. Results show that the flow over aircraft wings leads to large variations of pressure and temperature. Average pressure differences between the upper and lower sides of a wing are on the order of 50 hPa, which is a quite substantial fraction of cruise-level atmospheric pressures. Adiabatic cooling exceeds 20 K about 2 m above the wing in a case study shown here. Accordingly, extremely high supersaturations (exceeding 1000%) occur for a fraction of a second. The potential consequences for the ice microphysics are discussed. Because aerodynamic contrails are independent of the formation conditions of jet contrails, they form an additional class of contrails that might be complementary because they form predominantly in layers that are too warm for jet contrail formation.