More and more people are moving to cities, which now account for 80 percent of greenhouse gas emissions. To steer this rapid urbanization toward a greener future, major cities are increasingly turning to new, energy-efficient technologies.
Energy-efficient buildings offer the quickest route to reducing cities’ greenhouse gas emissions - here Singapore skyscrapers and Siemens’ Beijing headquarter.
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It would be difficult to imagine a greener city. Here, the inhabitants all live in one gigantic building that blends in perfectly with its immediate environment. Construction materials are all locally produced and fully biodegradable. A sophisticated arrangement of gangways, ventilation shafts, and layers of insulation ensures an agreeable climate inside, even when outdoor temperature variations are extreme. What’s more, it does so without having to consume a single kilowatt- hour of energy. In fact, the building is situated in such a way that only its narrow side catches the midday sun, thus reducing the effects of solar heating. Deep within the structure itself, residents tend huge gardens, which provide food for the entire city. Here, the sum total of the greenhouse gases produced by the population is merely the result of their digestive processes.
Sounds like science fiction? For termites and other insects, it’s been a reality since the beginning of time. These ingenious creatures are veritable masters of green urban planning. Their nests, which can grow as tall as seven meters, not only provide a home to millions of fellow insects; they are also extremely energy-efficient and built in total harmony with nature. In this respect, at least, termites are far ahead of us. "We need to learn that life in confined spaces and sustainability are not mutually exclusive," says U.S. architect and urban planner Daniel Libeskind. "Combining the two is currently the biggest challenge facing urban development."
In fact, many of today’s megacities are seemingly endless concrete jungles that continue to devour space and resources. Forecasts indicate that the number of megacities - those with at least ten million inhabitants - will increase from 22 to 26 by 2015. The majority of these are to be found in emerging and developing countries - in other words, places where sustainability hasn’t always been assigned top priority in the past. Here, the authorities often have limited means at their disposal to tackle the most urgent environmental challenges. These include improvements to local public transport, refurbishment of buildings, and renewal of power and water infrastructures.
Yet the battle to limit climate change could be fought most effectively in large population centers. Cities already account for 75 percent of the energy consumed worldwide and are responsible for 80 percent of greenhouse gas emissions. Today, architects such as Libeskind see a gradual change in attitude. "There’s a rethink taking place," he says. "Municipal authorities are now looking at more sustainable ways of shaping rapid urbanization. That creates a lot of potential for innovation." London-based HSBC bank estimates that around 15 percent of current measures to stimulate the economy worldwide are going into green infrastructure projects such as energy-efficient building systems (see article “Huge Growth Market for Green Urban-Infrastructure Solutions). At the same time, the latest findings in climate research may have also made cities wake up to the issue of sustainability. That’s because the impact of climate change - droughts, water shortages, and rising sea levels - would hit developing and emerging countries the hardest.
Singapore has been demonstrating how to conduct sustainable urban planning in a confined space ever since it gained independence in 1965 (see article “Green Test Bed”). The city state, which comprises an area smaller than Hamburg, Germany, is home to five million people. Nevertheless, or perhaps because of this, it is one of the greenest cities in Asia. "We have high population growth, like other cities, but hardly any raw materials and a land area of only 710 square kilometers," explains Richard Hoo, Group Director of Strategic Planning at Singapore’s Urban Redevelopment Authority. "That’s why it’s always been crucial for us to grow in a sustainable way." Singapore’s population has increased by 70 percent since 1986.
According to Hoo, the area of green cover has also grown by 50 percent over the same period. Besides having numerous parks, which provide a welcome retreat for the city’s inhabitants, as well as a natural air conditioning system, Singapore also promotes the use and development of energy- efficient technologies.