Of course the pollution is less than that from traffic. But that doesn't mean we shouldn't care about it. Cheap flights and airline profits mean that our environment is degraded without consulting or any benefit to us. I feel that we have been skilfully shafted without noticing it by the airlines and BAA with the full knowledge and co-operation of the various national governments and probably local government as well. As it seems it's not a matter of concern to many people, apparently there's not a lot that can be done about it.