Efforts to reach the world's first climate deal governing the aviation sector got underway in Montreal on Tuesday amid criticism from environmental groups that a proposal doesn't go far enough.
Delegates to the UN International Civil Aviation Organization general assembly are being asked to approve, in two weeks, a program for the industry to become carbon neutral after 2020 and to halve net emissions by 2050 compared to 2005.
Canadian Transportation Minister Marc Garneau said strong approval by the 191 countries participating in ICAO will be a significant achievement and send a strong signal to other sectors examining their environmental footprints.
So far, an estimated 58 ICAO countries are agreed to provide their support to a proposal that has been watered down to a voluntary system in the first five years.
However, several large developing countries, including India, have voiced concerns.
Aviation accounts for two per cent of global greenhouse emissions. However, the amount of travel by air is forecasted to double by 2030 with more than six billion passengers.
