The International Civil Aviation Organization Council, consisting of 36 nations, agreed September 4 to have countries design a market-based mechanism to curb greenhouse gas emissions by 2016 in order to implement the plan in 2020. The plan is meant to satisfy concerns, including those by the U.S., about the European Union Emissions Trading System from aviation; under the plan, the scheme would only apply to EU airspace before 2020. The full organization will consider the proposal in Montreal on September 24.