Airlines seek to downplay global warming impact of aviation[fr] 

The UN Intergovernmental Panel on Climate Change (IPCC) estimated in a 1999 report that air traffic contributes to about 3.5% of the total human activities linked to climate change. This share is expected to grow to 5% by 2050.

In Europe, the share of aviation in greenhouse gas emissions is still modest, at about 3% of the total, according to the European Commission. But it is concerned that emissions are growing faster than in any other sector and risk undermining progress achieved through emission cuts in other areas of the economy, mainly in the energy sector and energy-intensive industries.

The International Air Transport Association (IATA),  which represents the global airline industry, on 25 April issued a 5-point brief aimed at killing what it describes as "some persistent myths" about the environmental impact of aviation.

The five "myths" identified by IATA centre around allegations that air transport is a major source of greenhouse gas emissions. Here are some of the figures that IATA puts forward to "debunk" the myths:

• Air transport contributes a small part of global CO2 emissions-2%
• Over the last 40 years emissions per passenger kilometre have decreased by 70%
• Airline fuel efficiency improved 20% in the last decade
• 80% of aviation emissions are related to flights over 1,500 km for which there is no alternative mode of transport

The IATA arguments are however contested by the European Federation for Transport and Environment, an environmental NGO. In a point-by-point rebuttal, T&E argues that:

• The 2% figure refers to CO2 emissions, not other climate impacts such as aviation-induced cirrus clouds 
• The 2% figure is from 1992 which fails to include the explosion in growth of global aviation in the last fifteen years
• The true global contribution to climate change of aviation is between 4 and 9%, depending on the impact of aviation-induced cirrus clouds
• Aircraft fuel efficiency has not improved at all. Typical passenger aircraft of the 1950s were as fuel efficient as typical modern jets.