As airports grow, argues Kasarda, they become more city-like. The shopping zone of Indianapolis International, he says, "really gives the feeling" of a town square. There are 6000 weddings a year at Stockholm Arlanda, the Rijksmuseum exhibits art in Amsterdam's Schiphol, and the London Philharmonic is performing at Heathrow. "If you want to see the future," he says, "look at the Squaire" - a sleek, glassy slug in Frankfurt where KPMG has moved some of its operations, on the basis that it is only a few minutes' walk from workplace to check-in.
Kasarda's favourite examples of an aerotropolis are Las Colinas, Texas, which is handily placed for Dallas Fort Worth and "hosts four Global Fortune 500 headquarters", and New Songdo, a development built (with advice from Kasarda) near Incheon airport in South Korea. Also, Dubai, "an airport with an emirate attached", and Singapore, whose growth has been assisted by its airport.
He shows a plan of an ideal city, with runways at its centre and "aerolanes" connecting such things as "E-fulfilment facilities" and a "medical and wellness cluster". This city is shown as being built on virgin greensward, a site very unlike London, which already has a large number of buildings and services, and people who might resist relocation. Kasarda calls the existing fabric "sunk cost", which roughly means "money down the drain", before acknowledging they might have some value: "You can't get rid of it, so you have to leverage it as best you can."
Kasarda is right that international air travel is a growing force, and that London will suffer if it fails to find an intelligent response. But, as described, aerotropolis is chilling: a model of a city driven by a combination of business imperatives and state control, with the high levels of security and control that go with airports. Under the dictatorship of speed, individual memory and identity are abolished. An airport shopping mall is not like a town square because everything there is programmed and managed, and spontaneity and initiative are abolished.
According to Kasarda's 10 points for planning aerotropolises, "thematic architectural features, public art and iconic structures should make aerotropolis developments interpretable, navigable and welcoming". New Songdo includes a Jack Nicklaus golf course and areas modelled on Venetian canals and Central Park. But, according to sociologist Richard Sennett, it's a "stupefying" place where "there is nothing to be learned from walking the streets".
Nor are airport cities precisely pure expressions of the market, as some 19th-century railway towns were. The South Korean Government has invested heavily in New Songdo, which has yet to prove it will be the humming metropolis promised by its makers. Of the plan to build a new airport in the Thames estuary, Kasarda tells me that "most airport transportation connectivity will need to be based on public funding, and this will be expensive. I know of no significant commercial airport that has been privately built that had not received substantial public funding support, at least indirectly."
The deal, in other words, is this: taxpayers would be expected to pay handsomely for an environment created almost entirely to serve the needs of business. If they don't, as Kasarda says of a Britain without enhanced airports in London, "the city and nation will become markedly weakened in the coming decades". And if the public does foot the bill, the bet might not pay off. "The Thames estuary airport is a high-risk but potentially very high-return option," says Kasarda.
London can never afford to be complacent - not least about the state of its airports - but the aerotropolis idea offers a too simplistic view of cities. I hope that Boris Johnson understands.
- Observer