Researchers are studying the effects condensation trails, nitrogen dioxide and other aircraft emissions have on global warming.

The UN's Intergovernmental Panel on Climate Change (IPCC) has estimated that the damage by these emissions is between double to four times greater than the impact of carbon dioxide alone.

Previous research by a German aviation research institute found that the white trails often seen criss-crossing the sky could cause more climate damage than carbon dioxide. The trails broaden after about 30 minutes to form banks of cloud that prevent heat from escaping upwards, causing a greenhouse effect.

Nitrogen dioxide forms ozone, a greenhouse gas, when emitted at altitude.

A British Airways spokesman said, “While research has given us a solid understanding of the effect carbon dioxide generated by flying has on the environment, the climate impact of our nitrogen dioxide emissions and other effects is less well understood. Recognising that these aircraft non-CO2 effects may be important, we are committed to improving scientific understanding in this area by supporting and engaging in research initiatives. We are looking at whether we can use our aircraft to assist in the collection of atmospheric data.”

The airline is also supporting workshops said to cost £50,000 organised by the University to pinpoint gaps in knowledge and work out a plan to ensure that  scientific understanding of aircraft non-CO2 effects is robust by 2012”.

Some experts think the results of the study could result in much higher environmental surcharges on tickets than expected.

Ministers from the European Union agreed to include all flights arriving at or departing from EU airports in the European emissions trading scheme from 2012 in December 2007.  But the scheme, in which companies buy and sell permits to pollute, only covers carbon dioxide emissions and may add less than £6 to the average fare for flights within Europe and less than £25 to longhaul fares.

Should airlines be made to pay for their other climate change emissions, the cost to the passenger could quadruple.

Professor John Green said that condensation trails could be avoided by diverting aircraft around areas of cold, moist air— although, this could result in greater consumption of fuel and could lengthen flights.

He urged Eurocontrol, the European body that oversees air traffic control, to study how aircraft could be routed to avoid forming trails without suffering an excessive fuel penalty.

Green is a member of Greener by Design, an aviation industry group that promotes technological solutions to environmental problems.

BA also announced that it had made its voluntary carbon offsetting scheme easier to use.  Passengers will be able to offset their flight emissions in a single transaction when booking their ticket online. Under the scheme, passengers’ donations would be given in support of a wind farm in China and forest protection projects in Brazil.  THE END.