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To sustain something means to keep it in existence.
When we talk about resources, sustainability means living today in a way that will let people meet their needs in the future. For example, look at paper. It’s usually made from trees. Sure, new trees can be grown. But if people use too much paper, we might cut down trees faster than new ones can grow. Then our use of this resource would not be sustainable. Also, it takes a lot of water and fuel to turn trees into paper. It takes even more fuel to get that paper to you.
We still have plenty of trees, but other resources are running low. We’re nowhere near sustainability, but change is taking place.
Energy
◀ Sweet! A U.S. research team has made a battery that runs on sugar. This “bio-battery” is cheaper to make than other batteries. It’s also refillable and good for the environment. One scientist says our gadgets could be running on sugar within three years.
Transportation
◀ Many cities in the U.S. and around the world promote bike-sharing programs. You can rent a bicycle for short rides. Many people use them to get to work. You can get a bike at one place and drop it off at another. New York’s program is one of the largest. It has 6,000 bikes at 330 parking stations.
Food
▲ Ever seen a farm in a city? More than 10 percent of the world’s food is now grown in cities. Hanoi is the capital of Vietnam. Eighty percent of the fresh vegetables there come from farms in the city. So does half of the eggs, pork, and poultry.
Water
▲ Some people pay for water. Others just save it when it falls from the sky. In Bowral, Australia, people gather 70 percent of the water they need in rainwater tanks attached to houses.
◀ Many people in dry areas want to conserve water and power. Xeriscaping saves water and energy. It’s also good for the environment. It uses native plants and trees, plus others that don’t need much water.
Architecture
More homes that only need solar energy are being developed and built around the world. The homes get all the power they need from the Sun. Even better, they make enough extra energy to power an electric vehicle. ▶
City of the Future?
▲ Today, half of Earth’s people live in cities. More people are moving to cities every day. City people use 75 percent of all the resources consumed. But they live on only 2 percent of Earth’s land. We need a new kind of city, where people use less of Earth’s resources. In Tianjin, northern China, such a city is taking shape. Tianjin Eco-City is being built on a piece of land about half the size of Manhattan. All its energy will come from wind, solar power, biofuel, and recycled waste. It will have lots of bike lanes and footpaths, so cars (and their fumes) won’t be necessary. Buses will be free and electric. When the city is finished in the 2020s, it will be home to 350,000 people. But Tianjin Eco-City is just one place. Until all cities have programs to help conserve Earth’s resources, we need to do all we can. So let’s all reuse, reduce, recycle, and conserve Earth’s resources. We only have one planet, after all.
