By 2050, 66% of the world’s population will live in urban areas (54% lived in cities in 2014), and our cities will increase, both in number and size, according to a UN report. As a reason for this trend, Saffa Riffat et al. state in their review that, “Urban areas are more attractive than rural areas for many people in terms of job opportunities, improved living conditions, multicultural environment and dynamic life.”
This development will not only have positive but also negative effects. Problems that are already visible today—like land and food shortages, heavy traffic loads, urban/global warming, and air pollution to name a few—will worsen in the future. Consequently, scientists and practitioners have been looking into measures to address these challenges. Some of their concepts have already been implemented; some will likely become reality in the near future. Yet others sound like they could have been taken from a science fiction movie, but who knows what the future will bring?
Measures to address problems of future cities
One approach involves buildings that cover their total energy consumption with renewable energy sources. One innovative example is the ZCB (Zero Carbon Building) located in Hong Kong. As one might expect, their main energy sources are photovoltaic panels and biofuel. But who would have guessed that the biofuel used is made of waste cooking oil produced in Hong Kong? Even their lift regenerates energy when braking and, under certain conditions, when moving up or down. And this is just a very small selection of the features they have applied to achieve the goal of zero net carbon emissions.
Another problem that is already being addressed is the rising demand for food in combination with a shortage of (agricultural) land. The solution here is “Vertical Farming,” which is based on farms that grow upwards instead of outwards. Today’s largest vertical farm is located in Michigan, USA and is home to 17 million plants.
Growing traffic problems are another issue that needs to be resolved in the future. In this context Saffa Riffat et al. mention technologies such as self-driving vehicles, electric vehicles, and more exotic approaches including the Aero-Mobil flying car and the Aero-Train, which is train and plane in one.
Concepts for sustainable future cities
These sample measures described above can all be applied to existing cities, but of course building sustainable cities from scratch is also a concept that is being taken into consideration. One such project, called Masdar City, is already nearly a reality. Unsurprisingly, this city will be located in the wealthy and ambitious Emirate of Abu Dhabi. The 7-square-kilometer city with ~40,000 inhabitants is intended to be the first low-carbon and zero-waste sustainable city in the world, and solely powered by renewable energy.
Whereas we can likely all envision a city like Masdar City coming true, there are also projects for what they call “futuristic cities,” which require a little more imagination. These cities are planned to be located underground, underwater, in the sky or afloat on the sea. While these seem to be concepts more likely to be found in science fiction movies than in the real world, a Japanese company called Shimizu Corporation is convinced that underwater cities for example could become a reality by 2030. They have developed the design for what they call “Ocean Spirals.” Ocean Spirals would accommodate 5,000 inhabitants living in 500-meter diameter spheres hooked up with so-called “Infra Spirals” connecting the sphere to the seabed, supplying it with electricity, fresh water and/or food.
For a more comprehensive overview of the challenges of and solutions for sustainable future cities read the full article here: “Future cities and environmental sustainability” and also have a look at further articles published in Future Cities and Environment.