London, May 6 : An unpublished study has revealed that airlines are pumping 20 per cent more carbon dioxide into the atmosphere than estimates suggest, with total emissions set to reach between 1.2 billion and 1.5 billion tonnes annually by 2025.
According to a report in The Independent, the aviation industry's failure to curb its soaring carbon emissions could lead to the "worst case scenario" for climate change, as envisaged by the United Nations.
The report, by four government-funded research bodies, is one of the most authoritative estimates of the growth of pollutants produced by the industry.
Combining data produced by the leading emissions-modelling laboratories in the US, Britain and France, the study found that the number of people seriously affected by aircraft noise will rise from 24 million in 2000 to 30.3 million by 2025, despite the introduction of quieter jets.
It also found out that the amount of nitrogen oxides around airports, produced by aircraft engines, will rise from 2.5 million tonnes in 2000 to 6.1 million tonnes in 2025.
"Growth of CO2 emissions on this scale will comfortably outstrip any gains made by improved technology and ensure aviation is an even larger contributor to global warming by 2025 than previously thought," said Jeff Gazzard, a spokesman for the Aviation Environment Federation, the group that uncovered the report.
"Governments must take action to put a cap on air transport's unrestrained growth," he added.
The authors of the new report have predicted that CO2 will rise from its current level of 670 million tonnes to up to 1.48 billion tonnes by 2025. This exceeds the previous estimate, made in 2004, of 1.03 billion tonnes by 2025.
The growth in aviation CO2 means that the highest forecast for aviation emissions produced by the International Panel on Climate Change will be met or exceeded.
According to the spokesman for the International Air Transport Association, "With fuel costs doubling in the last year, airlines already have an incentive to work towards greater efficiency."
"There has been a 70 per cent improvement in fuel efficiency in the last four decades. Aviation is a benchmark of environmental responsibility for others to follow," he added.