This week's video is about trends and needs. The main trend is all about how more people are moving to the big city. According to a nonprofit organization called the Population Reference Bureau, only about three percent of the world's population lived in cities back in 1800. By 2050, as much as 70 percent of the world could be making urban areas their home.
The United Nations projects that the world's population at that time will be between 7.4 billion and 10.6 billion people by 2050. Those cities are going to get pretty crowded. We asked ourselves a question: How could we help make cities more self-sustainable?
We may have to face a hard truth -- it might be impossible to create a truly self-sustainable city of significant size unless we have an energy surplus. That's because cities need a lot of energy to run the way we're used to. Plus, growing and distributing food requires even more energy. If there's no energy surplus, it may make more sense economically to rely on surrounding areas for resources like food.
But we can help offset those needs. One potential strategy is vertical farming. The concept is pretty simple -- design farms that can exist within a vertical structure like a skyscraper. Build up rather than out, maximizing the physical footprint of the space your building occupies. A vertical farm could provide fresh food to a city's inhabitants, reducing transportation costs, environmental impact and risk of spoilage.
Critics of the vertical farming idea point out that growing food in an urban environment -- particularly in a skyscraper -- would require a lot of energy that you'd get for free in a traditional farm. Vertical farms wouldn't receive as much direct sunlight as a normal farm, meaning you'd have to pour in more energy to provide artificial sunlight to make up the difference. Irrigating and harvesting the crops would also require energy. But if we can make vertical farms work in a way that makes sense both economically and from an energy efficiency perspective, it could help offset -- though not completely meet -- our food needs in urban areas.
Another idea we explore is how a city could reduce its energy needs overall. It's already possible to build small net-zero energy buildings. Those are buildings that don't need to draw energy from the power grid because they generate as much power as they need to operate properly. These buildings use power-saving techniques like passive solar harvesting to help heat and cool the interior throughout the year. They also use renewable energy sources like solar power or wind turbines to generate electricity.
It's even possible to build a positive-energy building that generates more power than it needs. With those buildings, you can sell electricity to the power grid. The question is can you incorporate these designs into something as massive as a skyscraper?
According to the firm Skidmore, Owings and Merrill, LLP, the answer is "yes." That's the firm that designed the Pearl River Tower in China. The tower is a 70-story building that incorporates solar harvesting, wind turbines and other techniques to reduce power consumption to a net zero. If the claims are true, it could mean that future buildings around the world will also use these same approaches to reduce or eliminate power needs. That could make an enormous impact both economically and environmentally.
The more time, effort and thought we put into urban planning and design now will benefit us further down the road. While we may one day solve our energy needs with technology, it's a good idea to reduce those needs as much as we can to put less stress on the environment. And as for urban and vertical farms, I love the idea of being able to buy a fresh avocado that was grown right down the street -- or maybe two floors above my apartment.