A first-ever global deal on curbing the airline industry's rising carbon emissions was agreed Friday, the International Civil Aviation Organization said, though hammering out the details could take years.
The full agreement is not scheduled to take effect until 2020 but the most contentious issues have been resolved, officials said, as the ICAO's full assembly met behind closed doors in Montreal.
The deal "is an historic milestone for air transport and for the role of multilateralism in addressing global climate challenges," ICAO Council President Roberto Kobeh Gonzalez said in a statement.
Air transport "now becomes the only major industry sector to have a multilateral global market-based mechanism agreement in place to help govern future greenhouse gas emissions," he added.
Leading up to the vote, China and India had joined the United States and Russia in balking at a European Union push for a carbon levy on flights within three years.
But at midday (1600 GMT), after some 1,400 delegates representing 170 member states voted on the executive committee's resolution, officials said the plan had been passed and details of the accord would follow.
"The good news is (in) having concluded a general agreement that includes China and India," a diplomat involved in the negotiations told AFP.
Aviation accounts for around three percent of global CO2 emissions but the ICAO forecasts that by 2050 emissions will have risen between four and six times the levels they were in 2010.
Last year, the EU suspended its CO2 Emissions Trading Scheme (ETS) for intercontinental flights, after facing a storm of criticism.
Under the EU's ill-fated arrangement, airlines flying in EU airspace were required to buy pollution credits to cover 15 percent of their CO2 emissions for the entire flight, wherever it originated.
Several nations rejected the scheme that threatened to tip into a trade war.
The ICAO resolution "is a strong message to Europe after it lost three votes on its proposals," a negotiator said.
According to a draft text of the agreement submitted for consideration at the ICAO meeting, countries must agree by 2016 on a global market-based mechanism and reject all regional schemes, according to the negotiator.
The measure is to be accompanied by a series of technical and operational steps to reduce emissions, said a European Commission statement.
Specific proposals under consideration for curbing CO2 emissions include a carbon tax and a carbon trading system.
The European Union would thus have to abandon its more ambitious ETS and adhere to the new global system for curbing greenhouse gases linked to global warming.
Even so, European Commission Vice President Siim Kallas praised Friday's outcome.
"I am very pleased that after long and hard negotiations we finally have a global deal on aviation emissions," Kallas said in a statement.
"This is good news for the traveling public, good news for the aviation industry, but most importantly it is very good news for the planet," he said.
Furthermore, he added, the deal averts a "damaging conflict among trading partners."
European Commissioner for Climate Action Connie Hedegaard meanwhile congratulated the ICAO members.
"After so many years of talks the ICAO has finally agreed to the first-ever global deal to curb aviation emissions," she said.
In addition to the mechanism for curbing emissions, the accord also calls for promoting the use of better alternative aviation fuels and fuel-saving navigation.
There is also an exemption clause that provides a "fair and equitable solution" for a number of countries facing "special circumstances or with limited capabilities," said the EU.