I don't think they're doing any good at all. In fact, I think they are misguided.
http://news.bbc.co.uk/1/hi/uk/6952542.stmIn this story, they say that they are not targeting holidaymakers because they have no quarrel with them. Do they not understand supply and demand? The holidaymakers create the demand that the new terminal would help supply.
They are targeting freight because of the number of shipments of goods being flown in. Supply and demand. Those goods wouldn't be shipped in if it wasn't for people buying them.
In trying to garner public support by saying things like this, they're letting down their cause, if you ask me. If they are opposed to a new terminal, then EVERYONE is their target because EVERYONE will use it.
I hate to break it to them, but holidaymakers contribute to climate change too!