Carbon dioxide emissions from airplanes, a study has revealed, are set to become a major factor in global warming in the future.
The first new projections of future aircraft emissions in 10 years predicts that carbon dioxide and other gases from air traffic will become a significant source of global warming as they double or triple by 2050.
Bethan Owen and colleagues note that aviation is not now one of the main drivers of global warming, with international aviation (source of 60 percent of carbon dioxide emissions from aircraft) not even included in the Kyoto Protocol.
Global air traffic currently contributes to between 2 and 3 percent of carbon dioxide emissions - the main "greenhouse" gas linked to global warming.
The scientists' computer model forecast that emissions of carbon dioxide will likely double or triple within the next 50 years.
By 2100, carbon dioxide emissions could increase by up to seven times the current levels, they say.
"Even though there have been significant improvements in fuel efficiency through aircraft technology and operational management, this has been outweighed by the increase in air traffic," the study stated.
The study has been published in ACS' Environmental Science and Technology, a semi-monthly journal.