The European Union Emissions Trading Scheme (EU ETS) is a market-based approach used to control pollution for achieving reductions in the emissions of pollutants, it is the world's biggest scheme for trading greenhouse gas emissions allowances. EU ETS was launched in 2005 to combat climate change and is a major pillar of EU climate policy. It covers power plants, factories, etc. In January 2012 the EU ETS was extended to the airline industry. 

The Air Line Pilots Association, Int’l (ALPA) stated in a news release that “Protecting U.S. airlines and their employees from this harmful tax has been an extremely high priority for ALPA because of the scheme’s potential to cost U.S. airlines $3.1 billion over the next eight years and threaten airline pilots’ jobs,” said Capt. Lee Moak, ALPA’s president. “ALPA thanks Senators John Thune (R-SD) and Claire McCaskill (D-MO) for their steadfast leadership in advancing this bill. 

Under the aviation tax scheme, flights into or out of an EU airport, regardless of how long that flight is in EU airspace, would be subject to the program’s emissions cap and trade requirements. U.S. airlines would be required to pay an emissions tax to the EU Member State to which they most frequently fly, without any requirements that EU countries even use these fees in emissions reduction efforts. The United States Government and Congress continue to object to the forced participation in the EU’s plan.