Most cities will have to be retrofitted for the new urban age to allow them to accommodate more people and function efficiently with lower carbon emissions. In my next few columns, I'll be exploring some of the tactics cities are using to meet these multiple challenges and create truly liveable, human habitats. I'll be looking at slums, integrated transport, networked “smart” aids, water and energy provision, and green architecture construction.
Before I do, it’s important to note one point. As hubs of industry, transport and domestic and office buildings, cities consume a large proportion of global energy and generate more than 80% of carbon emissions. This geographic concentration of such a hefty proportion of emissions actually presents an opportunity for easier fixes. The more compact the city, the more energy efficient transportation and everything else is.
Reach for the skies
While suburbia was built around the automobile, the city of the Anthropocene needs to be built around efficient, low-emitting mass transit. But to fit 6 billion people into cities by 2050, they will have to rise upwards and reach the sky. These cities will increasingly feature skyscrapers connected by sky-bridges and corridors, served by elevated mass transit, with above-ground parks and gardens.
We’ll also make more use of underground space, already so riddled with cables, pipes, sewerage, subway lines and basements that fossil-hunters of the future will wonder what enormous creature burrowed and ate its way through the Earth to leave such tunnels. Some cities, such as Singapore, already have vast networks of malls descending several storeys under its streets.
But cities have always defined themselves by their skylines, whether the vast gold-plated Mayan temples of pre-Colombian America, the Dome of the Rock in Jerusalem, the mythical Tower of Babel, the steeples and spires of Europe or the Empire State Building in Manhattan.
The new cities of the Anthropocene are continuing this trend – more than 350 skyscrapers have been constructed since 1999, when Malaysia unveiled its twin Petronas Towers, then the world’s highest building. By 2016, the Petronas Towers won’t even merit a spot in the top 10. The current tallest building, at over 828 metres (2,716 feet), is the Burj Khalifa in Dubai, a sky-piercing structure of such immensity that it bears no relation to the human-proportioned Bedouin huts that peppered this location just a few decades ago. Three-quarters of the world's tallest buildings are now in Asia and the Middle East, over a century after the first skyscraper opened, half a world away in Chicago, then New York.
Scaling up doesn’t have to be as ostentatious as the Burj Khalifa, but it can be as innovative. Architects are using new materials, such as steel reinforced concrete, and new techniques, such as computer modelling, to see how their buildings will function when complete – for instance, how people will move around, live and relax in these towering houses. It allows them to tweak their designs early, such as improving escape routes or optimising apartment views and sun penetration. Cleverly designed, complexes holding thousands of people needn't feel crowded or cramped. Some skyscrapers attract birds and wildlife to sky-gardens, tens of floors up.
But in order to improve the sustainability of skyscrapers, architects need to go beyond the not-insignificant economy of scale achieved to include low-energy innovations. The Bank of America Tower, which opened in 2009 in New York City, achieves just that. It is made largely from recycled materials, captures its own rainwater and conserves water in other ways, such as with waterless urinals. It filters incoming and outgoing exhaust air, produces two-thirds of its own energy using an onsite, gas-fuelled combined heat and power generator, and conserves energy with insulating glass and “ice-batteries” in the basement, a system that uses off-peak energy at night to freeze water and allows it to melt during the day to cool the air in the building. The office tower has won a slew of awards and been given a platinum (highest) LEED (Leadership in Energy and Environmental Design) rating.
In the Anthropocene, buildings will need to incorporate features like these, and also meet our human needs in a liveable space, including sociability, calm, recreation and ease of movement. And do this hovering tens, if not hundreds, of storeys above the ground.