A Federal Aviation Administration official warned Thursday the European program to charge airlines for their emissions is a \"major impediment\" rather than a \"stepping stone\" to curbing climate change. Julie Oettinger, assistant FAA administrator for policy, international affairs and the environment, said European insistence on the contentious program has hurt negotiations with the United States and developing countries on reaching a worldwide agreement. \"I think that rather than being a stepping stone, I think it is a major impediment in moving forward in addressing aviation in the global outlook,\" she said at a U.S. Chamber of Commerce panel during a summit on aviation issues. The European Union\'s Emissions Trading Scheme sets a cap on carbon emissions and then charges airlines for flights to or from the continent. The industry group Airlines for America estimates the program could cost U.S. carriers $3 billion over the next decade. U.S. airlines have opposed the system as an unfair tax on flights outside Europe, and China and India have refused to participate in the program. But while the program began Jan. 1, the first payments aren\'t due until April 2013. Connie Hedegaard, the commission for climate action, told USA TODAY March 28 that a global compromise is possible through the International Civil Aviation Organization. Felix Leinemann, transport counselor for the European Union\'s delegation to the United States, warned at the Chamber panel that it would be difficult to change the Emissions Trading Scheme. But he repeated that compromise is still possible. \"The ETS system is not something that is carved in stone,\" Leinemann said. \"The system is quite flexible.\" Oettinger said Europeans would have to participate more in negotiations before a global solution could be found. \"If this is to be successful, and I think it can be successful, it requires a much more active and constructive engagement by the EU,\" Oettinger said.