Smash hit

“We suspect that BA is trying to muddy the waters with this research. Sponsors of research tend to get the results that they are looking for,” Mr Gazzard said.

Allowing airlines to buy carbon dioxide emission permits at the same rate as other industries could increase climate change because of the non-CO2 effects of flights, he added.

“Airlines and their passengers should stop cheating the planet and pay for all the environmental damage they are doing.”

Professor John Green, a member of the aviation industry’s Greener by Design group, which promotes technological solutions to environmental problems, said that condensation trails could be avoided by diverting aircraft around areas of cold, moist air — although, he added, this could result in greater consumption of fuel and could lengthen flights.

He called on 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.

BA also announced yesterday that it had made its voluntary carbonoffsetting scheme easier to use, with passengers able to offset their flight emissions in a single transaction when booking their ticket online. Under the scheme, passengers’ donations will be used to support a wind farm in China and forest protection projects in Brazil.

Catch-22

— Aircraft condensation trails form cirrus cloud, which traps heat

— During the day the cloud may have a positive effect by reflecting the Sun’s radiation. But at night it results in global warming

— Reducing cruise altitude by 6,000ft could reduce trails by 45 per cent but would increase fuel burn by 6 per cent

— Nitrogen dioxide forms ozone, a greenhouse gas, at altitude. Improving fuel efficiency — eg, by increasing burn temperature can increase nitrogen dioxide

Sources: Greener by Design; Times archives

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