Today, more than half of the world’s population lives in cities – that is 4.4 billion people! In the future, cities will grow even bigger. As the growing population needs even more of Earth’s resources, the time has come to find ways to make cities greener. A city is one that is able to take care of its people for a long
time. It should provide food, housing and electricity without harming the planet. Cities use a lot of power. Today, they use almost 80% of the world’s energy, most of which comes from burning . This is not sustainable in the long run as fossil fuels are a finite resource. Many scientists think that we will run out of fossil fuels within this century. Most importantly, they threaten the health and future of our planet by contributing to . To make cities sustainable, we need to power them with clean energy such as solar and wind energy. These energy sources are , which means that they will never run out. It is important
that we build cities in a way that reduces their impact on the environment. One way to do so is to build them with materials that are environmentally friendly and more . Low-flow toilets, for example, can save water, while a “cool roof” that absorbs less heat can save energy by naturally keeping the building cool. Green buildings may even have their own to generate their own energy from the sun. Waste management is a big problem in the world today. According to experts, we dump at least 2 billion tons of waste globally each year. Through recycling, reducing and reusing, cities can prevent waste from ending up in landfills. In San Francisco, for example, recycling and composting laws have helped the city cut 80% of its waste!
