Natural Cycles

When things happen over and over again, we call it a cycle. For example, we need food, air and water to live. The ways we get food, air and water are part of our life cycle.

All living things depend on each other. Animals need oxygen. They breathe in oxygen. They breathe out carbon dioxide as a waste product. Plants need carbon dioxide to perform photosynthesis. Photosynthesis is the way plants make their food, which is called carbohydrates. Plants use sunlight for energy and make carbohydrates out of carbon dioxide and water. Oxygen, which animals need to live, is a waste product of photosynthesis, along with tiny drops of water. We call this transpiration. So, animals depend on plants for oxygen, and plants depend on animals for carbon dioxide. Animals and plants both have to have water. This exchange is a natural cycle.

When natural cycles are changed, the plants and animals have to change, too. Making a change like this is called adapting.

Sometimes a change in a natural cycle is so big that the animals and plants don't have the time to change. Or, they cannot make the changes they need to make. That's often what happens when our environment becomes polluted. The plants and animals are unable to make changes and either die or driven off before they can change.

Our earth's five greatest environmental problems are causing changes that make it hard for animals and plants to adapt: air pollution, acid rain, water pollution, waste disposal and the loss of trees.

Scientists and international leaders agree that the year 2012 is a very important year for the environment. We have to begin cleaning up the earth now. If we don't, by the year 2012 it may be too late. Our earth is may never be clean and healthy again.

Air Pollution

Air pollution makes it hard for us to breathe. It is probably causing the earth to become warmer, which will change our climate. It even pollutes the water.

Global Warming

In November 1997, leaders in politics and science met in Kyoto, Japan, at the United Nations Conference on Global Warming. These world leaders met because they are concerned about the way polluted air is changing our climate.

Map of Japan, with a blinking locator (arrow pointing?) over Kyoto

To pollute means to make unfit for living things, especially by adding waste matter such as car emissions to the air or chemicals to the water.

The emissions being put into our air from cars and other sources like electrical and manufacturing plants can combine to create a layer of bad air. As more and more emissions enter the air, the layers close to the earth may get very thick so that we cannot see ahead of us or breath well. We call these thick layers smog.

At the same time, the emissions rise into our atmosphere and move all around the world, creating layers of "dirt" high up in our atmosphere. These layers create what is called a thermal blanket. This blanket keeps our earth warm (just like blankets keep us warm in a cold winter). That might seem like a good thing, but our earth has a natural process for keeping warm. The thermal blanket created by emissions is not natural. This blanket may make the earth too warm. If the earth is too warm, plants and animals may die. It can also change the places and times that rain falls, the amount of rain that falls, and all of our other weather patterns. Over time, if the earth's temperature rises even one or two degrees, trees, plants and animals (including us) will have to change the way they live and grow. The temperature will be too high and the rain patterns change. The rise in temperature is called global warming.

Acid Rain

Air pollution also causes acid rain. Rainwater picks up particles and gases when it falls through the air. If the air is polluted, the rainwater becomes polluted, too. Polluted rain is called acid rain.

Some acids are helpful. We have acid in our stomachs to break down and digest food. We use vinegar, an acid, to pickle cucumbers. Acids like these are help us. But, acids can also be harmful. If there is too much acid in garden soil, plants will not grow. Some acids will burn your skin.

Acid rain is harmful rain. When it falls on living things--plants, animals and people--it can harm or kill them. Leaves burned by acid rain cannot make oxygen or collect carbon dioxide needed for photosynthesis.

Water Pollution

Did you know that the water we use today is the same water the dinosaurs used? We cannot create new water. For millions of years, the water we have has been used again and again. We have been able to do this because there are natural cycles that clean the water each time we use it.

People are causing our water to be polluted. Businesses and cities dump chemicals and waste products into our rivers, lakes and oceans. People throw trash--furniture, garbage, old tires, cars, old fencing, anything they can think of--into the water.

The acid rain caused by pollution poisons water on the surface of the earth. Beneath the earth are layers of dirt and rock that act as containers for water. We call them aquifers. Rainwater drains through the soil into the aquifers. We call the water in the aquifer ground water. Groundwater supplies wells and springs. It is a very important source of water for all the plants and animals.

Acid rain soaks into the soil. Like clean rainwater, it drains down into the aquifer. When it reaches the groundwater, the acid rain pollutes it. It becomes unusable.

What is the cure for acid rain? We have to clean up the air.

Waste Disposal

Two billion people live on our earth. Every person creates waste. Food packages made of cardboard and plastic. Aluminum cans. Worn out tires. Used paper. Broken down cars. Bent bicycle wheels. Old toothbrushes. Grass clippings. Leftover food. Old movie tickets. Almost empty containers of cleaning products. Whatever we throw away. Where does it all go?

In towns and cities all over the world, trash is put in a dump. A dump is a place where trash is left in one spot on top of the ground or in deep holes in the earth. The holes are filled with trash. This is done year after year, until there is no more room at the dump. Then, a new dump is begun. In some towns, there is no room left for dumps. Trash has to be moved to the dumps in other towns.

One of the worst problems with older dumps is that polluting chemicals were dumped there before any rules were made about how to handle

In some towns and cities where the space for dumps is running out, laws have been passed that make people recycle. Using something again is called recycling. (You'll learn more about that later.)

A lot of used plastic and glass can be melted and reshaped into new plastic containers, carpeting, playground equipment, and a lot of other useful items. Paper can be cleaned, soaked in water, and turned into new paper. The steel from old cars can be re-melted and made into new cars. There are as many ways to reuse things, as there are things to use! All we have to do is think.

Tree Loss

Trees are as important to human beings as food and water are. To keep city air cool and healthy, trees should cover at least 40% of city land. One tree can clean toxic emissions from the dirty air exhausted from an average car being driven 4,000 miles. In the United States alone, 1.8 billion trees are used every year—that’s 7 trees for every person!

Trees produce most of the oxygen on Earth. Trees keep our air breathable by removing carbon dioxide and pollutants. They add moisture through transpiration.

Trees reduce costs of using our resources. For example, shade trees save money and energy. The trees lining city streets can save up to 50% on air-conditioning bills during the summer. In cold places, trees provide windbreaks that can reduce heating bills by as much as 30% in the winter.

Trees conserve other resources. Forests hold soil in place. They keep rainwater from running off the land so that it soaks through to the aquifer. Trees keep the water from running off the land too quickly and help control floods. Trees take care of our soil and water.

Trees provide shelter, food, recreation, beauty, and homes for birds, insects, and other animals and, we must always remember, chocolate. (The cocoa tree, the source of chocolate, is now on the endangered species list!)

As important as trees are, we are destroying them much faster than they can grow without our help. Imagine how many trees are used all over the world. People cut down trees to make room for new farms, housing developments, highways and cities. Trees are used to make newspapers, computer paper, furniture, houses and many other products.

Whenever large parts of a forest are cut down, animals lose their homes and everything about the place where the trees grew changes.

Rainforests

Rainforests cover less than 6% of the earth, but provide a home for more than half of the Earth's plant and animal species. More than 80% of the Earth's land vegetation can be found in rainforests. What does that mean for us?

Rainforests are one of the more important environmental resources we have. They are the home for tropical fruits, nuts, hundreds of animal and plants, medicines we know about, and probably many medicines we haven't found yet. They are the home for unique groups of people who use the resources of the rainforests in very special ways. For example, in the Philippine rainforest a tribe called the Hanunoo have developed 430 rainforest crops. Another tribe, the Lua in Northern Thailand, use 21 different plants for medicine.

The rainforests are like a frontier. We do not know what we will find when we explore the rainforests. However, we may not get the chance. Less than 50 years ago, rainforests covered 14% of the Earth's land--more than twice the land they cover now! Do you know how big a football field is? Well, every second of every minute an area as large as a football field is stripped of rainforest! The trees are cut down to provide exotic (exotic means unusual and beautiful) wood for furniture. Land is cleared so that cattle can graze. Trees are destroyed so that things like sweet potatoes can be grown. Hundreds of special animals and plants disappear every year because the rainforests are cut down.

If you would like to know more about how to help the rainforests, you can contact:

RAINFOREST ACTION NETWORK
221 Pine St., Suite 500
San Francisco, CA 94104
415-398-4404

Environmental Report Cards

KEC Kids get report cards all the time. Report cards help you know how well you are doing learning a particular subject. Unless you are different from other students, you would like to see straight As on every report card you get.

You can grade the way you, your family, your school and your community treat the environment. Do they get straight A's? If you want to find out, use the checklist below to rate how well they do.

For more information on the topics listed in the Report Card, look under Your Environment in this web site.

This report card can be used to grade homes, offices, religious institutions, schools and other places. It can be copied and distributed.

If you answer "yes" to fewer than 25 questions, that's a failing grade. If you answer "yes" to more than 40 question, you pass with flying colors. If you answer "yes" to all the questions, you are a real KEC star!!! And you should let us know about it, too!