Scrooge, if BAA slows down on a third runway, it will take a VERY long time for it to happen. Even as it is, it's going to take years to overcome all the total and utter idiots who complain about living under a flight-path (despite moving there after the airport) and yet do not want to move out to somewhere without this inconvenience to make way for the runway.
Plus, everyone bitches about extra carbon emissions but, in the short-run, it may help (excluding construction) as a/c won't have to sit on the taxiway with engines running for as long and won't have to hold for such a long time. In the long run, airlines will probably have to switch to biofuel anyway so emissions will be less of an issue in any case.
Besides, if we don't take advantge of extra demand, it will simply go to CDG,FRA, AMS and we will lose out. In addition, people don't want expansion at LHR and yet complain about the state of it the whole time.
Thanks for the link, Paul[y]
45.