70 Our Green Future

CHAPTER 1 Green Design SOME YEARS AGO GREEN WAS SIMPLY A COLOR. NOW IT'S MUCH MORE! In the second part of the 18th century, some parts of the world started to change very quickly. In Western Europe, new ways of farming were invented, and many factories were built. Different kinds of machines did work that people and animals had done before. Railroads and better roads brought everyone and everything closer together. Coal and oil became extremely important in everyday life because they were needed for all the new machines. Towns grew quickly and many houses, schools, and hospitals were built. Over time, people were able to earn more money and they were able, of course, to spend it, too.

By the late 20th century, life in many countries was much more comfortable than it had been two and a half centuries earlier: big cars, fast planes, electric refrigerators, and supermarket vegetables already washed, cut up, and covered in plastic! If something was broken, people could just throw it away and buy a new one. Life had never been so good— or so we thought. In the 1970s, some people began to feel very worried. What would happen if we continued using the Earth's natural resources as if there were no tomorrow? One day, there would be no more coal or oil left. What was the pollution from homes and factories doing to our environment? Greenhouse gases were changing our climate. Maybe the comfortable life we had made for ourselves was, in fact, a great danger for our world. And so green thinking was born, a big idea that touches governments all over the world, and a small idea that touches us all in our homes. People decided it was time to work with the Earth instead of against it.

CHAPTER 2 New Materials, New Ways WITH NEW MATERIALS AND NEW WAYS OF USING OLD MATERIALS, WE CAN START TO BUILD A GREENER FUTURE. Traditional buildings are made from different types of wood, stone, and metal. This can be a problem if we use too much of them. It takes a lot of energy to get these materials from the Earth and to move them from place to place. So, green architects have to think of new ways of building. They often choose renewable materials materials that the Earth replaces quickly. Some kinds of trees take 80 years to grow fully. Using wood from these trees is bad for the environment. However, wood taken from the bamboo plant is perfect for green building. It is one of the fastest growing plants in the world, sometimes growing one meter in only 24 hours.

Different ways to insulate buildings have also been found. Engineers are using renewable and recycled materials, such as old newspaper. The newspaper is cut into very small pieces. The pieces are blown into the space behind a wall with a special machine. The tiny pieces fill even the smallest hole. This stops the cold wind from getting into a building and the heat from getting out. Straw is also used to insulate wooden buildings, making them about 75 percent more energy efficient. Interestingly, straw protects a building from fire, too. No air can get into the wall, so a fire cannot pass through it either. Green building materials should also last for as long as possible, and there are ways to help this happen. There is a special type of glass for buildings that acts like a large pair of sunglasses. When sheets of this glass are put around a wooden building, they protect the wood from the heat of the sun. This helps control the temperature and also reduces the need for repairs.

A material called fly ash is also useful. This is the waste material that comes from burning coal. Around the world, a lot of coal is burned for energy. This makes a lot of fly ash. Rather than pouring this ash into the ocean or landfills: builders can mix it with concrete. This reduces the amount of other materials in the concrete. It also makes the floors and walls of buildings very strong and thick. These floors and walls need fewer repairs over time. But green building is not just about how we use natural materials; it is also about saving energy. For example, engineers have invented new ways of keeping buildings warm. Pipes with hot water running through them are put under the floor. Heat from this water then goes up through the floor and helps heat the building. This is called radiant heating.

Engineers have also thought of clever new ways to turn the sun's energy into electricity. These days, it is not unusual to see solar panels on the roofs of buildings. But many green buildings now have solar tubes instead of traditional skylights. These tubes are like pipes for sunlight. Using mirrors, they carry light from the sun all over a building, reducing the need for electric lighting.