The 8th grade will be beginning the year with a unit on water, and we'll be studying water for about two months! That seems like a long time to learn about something so simple! But there is more to water than meets the eye. In fact, the quest to solve the world's water problems is one of the biggest challenges of the 21st century.
You probably remember learning about the water cycle. (If not, here is a quick review.) There is never any new water made on Earth; the same water just loops around and is "recycled" over and over again. This means that water is a finite resource, meaning there is a limited amount of it that is available for us to use. So, it is very important that we take care of the water we have!
"But wait, Ms. Ewing," you may be saying. "When I look at a map, it seems like the whole world is covered with water!" You're right, of course. About 70% of our planet is covered with beautiful water. But 97.5% of it is salt water! We can't drink that! So only 2.5% of the Earth's water is even freshwater, and most of that small amount is frozen in the icecaps at the North Pole and the South Pole. And some of it is trapped as moisture in the soil under our feet, so we can't drink that either. At the end of the day, less than 1% of the water on Earth is available for us to drink. No wonder so many places on Earth are threatened because they don't have enough water.
This is a problem, because we all need water to live! When we don't take care of the water we have, people's lives are at risk. In previous centuries, people didn't know what to do to keep water clean, and in Chicago and other cities many people died from cholera and other diseases spread by unclean water. Now, we have the knowledge and the technology, and yet people all over the world are still sick dying because they can't get safe water. One out of five people in the world population lacks clean water, and 80% of diseases in developing nations comes from unsafe water, killing over 25,000 people every day. Children are especially at risk, because their bodies are still growing and can be vulnerable to these diseases. Click here to see how children in other nations are affected by this issue. Of course, in addition to needing water to drink (a lot-- about 16,000 gallons in your lifetime), we also need it to grow our food and produce goods in our factories. The last time you turned on a faucet, did you ever imagine how important that simple, familiar substance is?
Still want to know more? For a crash course on water, how it works, and why it's so important, visit the U.S. Geological Survey's water information page.
Or, if you think you're a water expert, take this quiz and see how much you really know....
