Over the past couple of years, Londoners have been watching what is now Europe’s tallest building soar into the sky. It is almost complete, and due to open in time for the London Olympics.

The Daily Mail has published on its website photographs of the Shard under construction, under the headline: “Reaching for the stars”.

Is the Shard, designed by architect Renzo Piano, “reaching for the stars”? I think it is. If it takes optimism and confidence to build tall, then the world is brimming with these qualities right now. According to the latest annual review on the Council on Tall Buildings and Urban Habitat website, all five years from 2007 to 2011 have been in turn record-breakers for the number of buildings 200 metres tall or higher completed worldwide in that year, with 88 constructed in 2011 alone. China of course is building fast, but other global cities such as Dubai, Abu Dhabi and Panama City are joining the boom.

The discussion at the Glass Steel and Stone website gives a flavour of the controversy surrounding the Shard: pride and admiration from some commenters, outright condemnation from others. Yet the negative comments convey to me a sense of sour grapes: moralising about vanity and money, or bemoaning the loss of spiritual values (symbolised by the Shard towering over Southwark cathedral or obstructing the view of St Paul’s). The Shard is a fait accompli which cannot be ignored, and the critics and traditionalists have lost the argument.

Buildings such as the Shard reach for the stars more than just symbolically. Certainly, they are direct visual evidence of a dynamic economy, particularly when, like the Shard and the Bishopsgate Tower (the Pinnacle) now building on the opposite side of the river, they are not just gigantic rectangular boxes but fascinating and unique artistic creations. Another residential tower is rising up directly outside the British Interplanetary Society’s London headquarters: the Vauxhall Tower.

A Britain capable of adding such sculptures to its skyline (albeit on Qatari money in the case of the Shard) is one which could also be capable of reaching for the stars in a far more literal sense with Skylon.

But they are more than that, which was brought home to me when I was reminded recently that modern skyscraper windows are sealed shut. The interiors therefore have to be fully air-conditioned: you are living in an artificial environment. Further, they are not always just office blocks any more. Renzo Piano, quoted on the Shard’s own official website: “This is my vision: I foresee the tower as a vertical city, for thousands of people to work in and enjoy, and for millions to take to their heart.”

From the ground up, the Shard contains retail shops, then offices, then restaurants, then a hotel, then private apartments, and a public viewing gallery at the top. You could live there, work there, shop there, eat there, and enjoy an incredible view of London from above, all without leaving the one building. A vertical city, indeed.

What this must be seen as is a prototype space colony. It happens to be parked on Earth, but many of the essentials of a self-contained artificial urban environment are there. It is not yet self-sufficient in terms of power or food production; these are innovations for the future. But the overall trend is unmistakeable: from our original home on the open African savannah, to the subsistence farming village, to the industrial city, and now to the “vertical city”. Humans are steadily removing themselves from dependence on their ancestral open-air environment and living in ever more artificial and manufactured environments: exactly the way we have to go if our children are to live in space.

The Shard resembles an enormous glass spire, but it is also not unlike a rocket poised for launch. Appropriate, I think.