About 71 percent of the Earth's surface is covered by water. Water in nature is saltwater and fresh water, but only three percent of that amount (数量) is freshwater. A lot of organizations are saying that people are running out of usable water, but few are taking this problem seriously.
Why should they? They see water everywhere. The average American family uses more than 1,140 liters (升) of water at home per day. However, in developing countries, nearly 900 million people do not have safe drinking water. Water shortages are, in fact, a bigger problem today than ever before. The human population has continued to grow and with it, its need for water. Global warming is making this problem more serious. Unless we all take it seriously, we will end up having to live on a blue planet without a drop of usable water.
From taking shorter showers to reusing water, there are many ways for you to save water. One more thing you can do is to reduce your use of "virtual water". Perhaps you have never heard of the idea of "virtual water." It means the water you use indirectly. We not just drink water and use it to clean all kinds of things; we also "use" it through the products we buy. To produce a piece of A4 paper, for example, we need about ten liters of water. The production of our food requires even more water. A cow needs to eat 1,300 kilograms of grain (谷物) for three years before it can produce 180 kilograms of beef. The grain requires water to grow, the cow needs to drink, and the farmer needs water to clean his farm. So behind each 230-gram steak dinner, there are nearly 3,600 liters of water!
It will make a big difference if you remove some meat from your diet and eat more fruit and vegetables instead. You are also saving water when you are writing on both sides of paper instead of just one. The world is running out of usable water. Every drop of it is valuable.
①The growing human population.
② The proper reprocess of water.
③ The great need for drinking water.
④ The increasing greenhouse effect.
