London Mayor Boris Johnson is chucking sentimentality out the window when he announced the plan to transfer the historic Heathrow airport. The area is set to be replaced with a new borough consisting of 100,000 homes to serve a quarter of a million of its population.

In justifying his plan, Johnson said in a press conference that the noise and congestion prove too much to handle. The airport's two runways are nearly brimming to capacity from the 69.9 million passengers in 2012 but building a third runway "would be the wrong thing to do" and a fourth runway "would be catastrophic."

He said he is backed by local sentiment when residents of two west boroughs near the airport voted 3 to 1 last May against expansion.

The mayor envisions the new airport somewhere on the north Kent coast, Isle of Grain or the Hoo Peninsula.

Of the three locations, he said, Kent "probably has the edge" because its close enough and planes would take off or land over the sea.