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To sustain something means to keep it in existence.
Where resources are concerned, sustainability means living so we can meet our needs today in a way that allows people in the future to meet their needs. For example, think about paper and paper products. They are made from the wood of trees. More trees can always be planted, so we don’t need to conserve paper, right? Not necessarily. If people consume so much paper that we use up trees faster than new ones can be planted and grown, then our use of this resource is not sustainable.
Today, we’re not in much danger of running out of trees, but we are running low on some important resources. We’re nowhere near achieving sustainability, but things are changing.
Energy
◀ Sweet news—a research team in the U.S. has invented a battery powered by sugar. This “bio-battery” is cheaper to make than other batteries. It’s also refillable and environmentally friendly, which makes it different from most batteries. According to one scientist, it could be powering our electronic gadgets within three years.
Transportation
◀ To promote cycling and bicycle commuting, many cities in the U.S. and around the world encourage bike-sharing. The programs let you rent bicycles for short rides. Bikes can be picked up in one place and dropped off at another. With 6,000 bikes and 330 parking stations, New York City’s program is one of the largest.
Food
▲ Over 10 percent of the world’s food is now grown in cities. In Hanoi, the capital of Vietnam, 80 percent of the fresh vegetables come from farms in the city, as well as 50 percent of the eggs, pork, and poultry.
Water
▲ In cities such as Bowral, Australia, rainwater tanks attached to houses gather 70 percent of the water the people need.
◀ Many people in the West and Southwest have xeriscape gardens. That’s a way of designing a garden to save water and protect the environment. It uses plants and trees that are native to the area, plus others that don’t need much water.
Architecture
More homes that run totally on solar energy are being developed and built around the world. These homes not only provide their own electricity but also produce enough energy to power an electric vehicle. ▶
City of the Future?
▲ Today, half of the people of the world live in cities, and more people are moving to cities every day. In any given year, city people use 75 percent of all the resources consumed while living on only 2 percent of Earth’s land. A new kind of city is needed, where people use less of Earth’s resources. In Tianjin, northern China, such a city is under construction. On a piece of land about half the size of Manhattan, Tianjin Eco-City will get all its energy from wind, solar power, biofuel, and recycled waste. A network of bike lanes and footpaths will help bring the city close to zero car emissions. Free electric buses will connect different areas. The plan is for 350,000 people to live in Tianjin Eco-City by the time construction is finished in the 2020s. However, until all cities help conserve Earth’s resources, people need to do all they can to reuse, reduce, recycle, and conserve Earth’s resources.
