If a third runway is needed then it nshoulld be built. I dont know why all these emotionally blinded environmental loonies are taken seriously. They talk of global warming yet Europe is going through the cooldest winter in decades. Modern aircraft are quieter more fuel efficient and safer. Perherps we should try driving across the atlantic if we're allowed to build a bridge that would do the job.
It is far more greener to fly 400 pax on a modern jummbo jet than than to have them drive if that were possible.