“The US government has very serious concerns” about the European Union Emissions Trading Scheme (ETS) carbon tax, FAA assistant administrator-Policy, International Affairs and Environment Julie Oettinger said Thursday.

“Our concern is not with difference of option with the objective … we are very serious about addressing aviation emissions in the US … the concern we have with EU ETS is the way it’s been designed and the way it’s been applied. We have concerns that it violates international law.”

Speaking to attendees at the US Chamber of Commerce 11th Annual Aviation Summit, Oettinger said the EU’s approach “has impeded the process on finding a global approach. We’re not opposed to emissions trading … it can be a very effective tool.”

Speaking as an EU delegate to the US, transport counselor, energy, environment and nuclear matters Felix Leinemann told attendees, “The ETS is not a tax, it is a system that has the only objective to reduce emissions, all the revenues will be used to combat climate change … As it is a market-based system, it allows a lot of flexibility.”

Airlines for America VP-environmental affairs Nancy Young countered, “It is a tax. What [the EU] is saying to us is ‘we’re going to impose upon the world … an EU policy.’ If we have tax upon tax … how can we do what we need to do not only to keep the industry strong … but to move the environmental ball forward?”

Leinemann added, “Obviously the EU would prefer a global solution … the law says exactly that, when there is consensus in ICAO, the law will be amended … This is just a step, a stepping stone to a global solution.”

When asked what it would take for the EU to amend ETS law in the face of a widely publicized global outcry, Leinemann said it would require a proposition from the legal system and the chamber to decide. “We are a little bit stuck in the process,” he said of the two sets of organizations that would need to agree on amending a law that was backed by all EU member states.

“The EU ETS covers about two-thirds of the world’s aviation emissions,” he said. “Any system that would go further than that … would maybe be a progress that would convince them to change the existing law.”