In the face of much international resistance, many expected the European Union (EU) to withdraw its plans to include emissions from aviation activities within its Emissions Trading Scheme (ETS). This proposal, known as the Aviation Directive, has amended the ETS to include emissions not only from European airlines, but any airline that operates flights into or out of EU airspace. The program only officially started January 1, 2012, but the EU instructed airlines to participate in a practice version, by reporting their total amount of CO2 emissions. Although the Aviation Directive has received several challenges towards the legality of their unilateral carbon tax imposition, the BBC is reporting that the majority of airlines have chosen to comply. With the exception of a few Chinese and Indian airlines, there is near full participation, which is a good sign for the future of the Directive. However, the airlines will not be asked to surrender allowances for their emissions until April of 2013. Some have predicted that if the EU remains insistent on collecting allowances from foreign carriers that a global trade war might ensue. The US and China have both instructed their airlines not to cooperate with the EU-ETS. However, if aviation can be successfully included within the ETS, it may have an added effect of rekindling talks of a global climate agreement.