Members of a cross-party parliamentary transport committee are warning that the European Union's emissions-trading scheme might prove a weak tool for pushing development of low-carbon air transport.
International flights using UK airports will need to be part of the trading scheme, a third phase in its development, from 2012.
But a Transport Select Committee report, The Future of Aviation, published today, cites conclusions from the National Audit Office that the first and second phases of the scheme were "ineffective in reducing carbon emissions beyond what would have occurred anyway".
The committee adds: "We are concerned that the [emissions-trading scheme] has an appalling track record and that it may prove insufficient to drive investment in low-carbon aviation, especially in these difficult economic times."
It states that carbon trading has had less impact on emissions than intended because caps have been set too high and initial allowances have been generous, and adds that the National Audit Office is "cautious about expecting too much" from extension of the scheme to aviation.
In its conclusions the committee has also called on the Government to "act decisively" to ensure older, noisier aircraft are phased out.