Policy brief (April 2014) by Armand de Mestral (McGill University). The European Union has finally opted to amend its Emissions Trading System (ETS) with regard to aviation. A new Directive was proposed by the European Commission and informally agreed to by the Council of the EU and European Parliament in March 2014. This policy brief looks at the key features of the modified EU ETS with respect to aviation. It then considers whether Canada has a legal obligation to comply with the EU ETS.