​The International Air Transport Association, which represents some 200 airlines, said the United Nations' aviation agency could agree on a new system when its 191 states begin their assembly in Montreal this week. The U.N.'s International Civil Aviation Organization (ICAO), which sets standards for air travel, is under pressure to make headway toward resolving one of the worst aviation disputes in years, pitting the European Union against its trade rivals. The ICAO meets in full once every three years. Greenhouse gas emissions from commercial flights are growing at a steep rate. The EU in 2011 came up with regulations to charge airlines for carbon emissions on flights to and from Europe over EU airspace. But it has suspended the scheme to allow opponents led by China and the United States to agree on a global plan to curb aviation emissions under U.N. auspices. The EU has threatened to reimpose the scheme if there is no deal. "If the assembly agrees what could be done from 2020, and what should be done in the meantime, I believe governments will work toward implementing that," IATA Director General Tony Tyler told reporters on a conference call on Monday. Earlier this month, preliminary negotiations led to a breakthrough ahead of the full ICAO assembly, but diplomats say some countries such as India are still unhappy about the plan which would allow the EU to charge only for its own airspace. China has suspended billions of dollars of orders of Airbus jets to protest the original European scheme. Tyler said agreement by countries on a global market-based solution, the details of which would need to be worked out, was preferable to regional measures such as the EU's controversial Emissions Trading Scheme. "We think that a global mandatory carbon offsetting scheme will be the simplest and easiest (market-based measure) to implement," he said. Without progress at ICAO, "we'll be back where we were over a year ago on the brink of a trade war," Tyler said. "That's a very serious risk which we clearly need to try to avoid." Failure to reach an ICAO resolution could also mean the "proliferation of regional schemes, of taxes, charges" by different governments to penalize airlines and passengers, he said. Pressure for a deal increased after IATA's members, some of whom reflect the views of their state shareholders, settled their own differences by calling for a single market-based system to offset growth in post-2020 emissions. Until recently, however, little progress has been made in the U.N. effort to craft an agreement to lower emissions from international air travel. The EU says its rules spurred international action and that curbing airline emissions is essential to meeting climate goals. One of the key remaining questions is to what extent small nations representing 1 percent or less of aviation emissions should have to take part in the reduction efforts. IATA was originally set up to help the U.N. harmonize aviation and acts mainly as a lobby for the airline industry. (Reuters)