officials of London's Luton airport have decided to charge a fee from passengers to combat the detrimental impact of their flights on the atmosphere. Those boarding their flight from the airport, which is mainly used by low-cost and charter airlines, will have to pay up to us $4.24 depending on the duration of their flight. "The money would be used to plant trees that would absorb some of the carbon dioxide ( co 2 ) emissions that result in global warming. We are trying to raise awareness on how aviation contributes to the greenhouse effect and climate change,' said Mark McClennan, Luton airport's head of environment. But Jeff Gazzard of the Aviation Environment Federation has doubts about the scheme being effective. "The drawback of this system is that the trees are not able to absorb all the co 2 that is emitted. Another disadvantage is that co 2 is just one of the emissions of the planes' engines. It accounts for only 30 per cent of the pollution problem caused due to aircrafts,' he added.