Rain contaminated with pollutants such as sulfur dioxide and nitrogen oxide. These gases come from fuels being burned at high temperatures and from car exhausts. When acid rain falls, it pollutes the environment, damaging trees, plants, fish, and other wildlife.
The variety of plant and animal species living in an environment. Scientists believe that there may be up to 30 million different species living on the planet, though most of them have not yet been discovered by people. Among the world's biomes, rainforests are the most biologically diverse, containing about half the world's species of plants and animals.
The area of the earth's land, water, and atmosphere that is able to support life. The biosphere contains a complex system of factors (water, plants, and solar energy, to name a few) that work together to generate the conditions that make life possible.
Harmful man-made gases that contain chlorine, fluorine, and carbon. They are found in refrigerator coolants and air conditioners as well as aerosol cans. They destroy the ozone layer, which protects life on Earth.
The generally prevailing weather conditions of a specific region over a long period of time. The climate of an area depends on factors such as temperature, precipitation, sunshine, winds, and humidity.
Decayed organic refuse. Many people create compost bins in their yards, where they throw out their food garbage. Composting makes garbage useful by turning it into a rich, moist soil that is great for growing plants but does not promote weed growth. Using this soil reduces the need for pesticides and other chemicals that can be harmful to the environment and to people.
Cutting down trees and not replacing them. It hurts the air quality because it reduces the number of trees that produce oxygen for us to breathe. Trees also help delay the greenhouse effect because they use carbon dioxide, which helps maintain air quality. In addition, trees protect the soil and hold it in place. See also reforestation.
An item that is made to be used once and then thrown away. Disposable items, like paper plates or plastic forks and knives, create unnecessary garbage. It is almost always better for the environment when you choose reusable items, like china plates and silverware, instead.
A community of plants and animals in an environment that supplies them with the raw materials they need to live, such as chemical elements and water. Ecosystems are the basic ecological units within the biosphere. They may be as small as a tidal pool or a rotting log or as large as an ocean or a continent-spanning forest.
The periodic phenomenon involving the warming of a mass of water in the Pacific Ocean along with a weakening of the trade winds near the equator. The movement of this warm water toward South America causes changes in weather patterns all over the world. These changes often have damaging effects, such as droughts in Latin America, Africa, and Australia, and extraordinary typhoons in Polynesia. In the United States, severe winter storms usually occur in California and the Gulf States during El Niño conditions.
Animals that may become extinct. A species of animal that is overhunted by people or whose food needs are not met will not survive. Each day three species on Earth become extinct, a rate 400 times greater than that 1,000 years ago. Though there are laws to protect endangered animals, it is often too late to save more than a few of the species. There are also laws protecting endangered plants and insects.
The power that makes things go. The kinds of energy we use to do things like power our cars and heat our homes can have an effect on the environment. Fossil fuels, such as oil and coal, are a widely used source of energy, but they cause air pollution. Solar and wind power are examples of “renewable” energy sources that are healthier for the environment. They occur naturally and do not have a limited supply. The six main resources that provide energy in the U.S. are oil, gas, coal, nuclear power, hydropower (water), and wood.
The Environmental Protection Agency, which was established in 1970, is a department of the U.S. government. Its job is to research and monitor the environment as well as enforce all laws that relate to the environment.
A natural source of energy such as oil, coal, and natural gas, that can be burned or otherwise consumed to produce heat. Finding and processing fossil fuels is expensive and when they are burned, they cause air pollution and acid rain. There are limited amounts of fossil fuels, so we must not waste them.
Scientists who study, measure, and weigh the things people throw away. They want to discover better ways to deal with garbage.
The predicted outcome of the increasing atmospheric concentrations of carbon dioxide and other “greenhouse gasses” released by human activities, such as burning fossil fuels and deforestation. Scientists estimate that global temperatures will rise a few degrees Celsius in the next century. Such a warming may cause changes that would affect the quality of human life, like rising sea levels and new infectious diseases.
The warming of the atmosphere that occurs when certain gasses act like the glass of a greenhouse, letting sunlight in and preventing heat from escaping. Though many people think the greenhouse effect is entirely bad, without it, the earth would be too cold. It is only when the atmosphere's natural balance is disrupted that the greenhouse effect makes the environment too hot.
A place that is natural for the life and growth of an organism or a community of organisms. A pond containing various fish and water plants is one example of a habitat.
Anything that is thrown away that can be potentially dangerous to people or to the environment, such as paint, oven cleaner, furniture polish, and pesticides. These materials can seep into our water supplies and contaminate them. Major hazardous wastes include medical wastes, sewage, and pollution from factories.
A non-native species whose introduction adversely affects human, animal, or plant health, as well as causing economic and/or environmental harm.
Valuable materials made by nature such as water, land, minerals, and plants. All are necessary for life.
Oil spills can occur from tankers, pipelines, and storage tanks, for any number of reasons. There is an oil spill almost every week. Spilled oil pollutes the water and is dangerous to wildlife, easily killing birds and fish.
A paper-thin sheet of ozone, an invisible gas, that surrounds the earth about 15 miles above its surface. A form of oxygen, ozone protects us from the sun's harmful rays. In recent years, scientists have learned that the amount of ozone in the atmosphere is decreasing, probably due to human use of chlorofluorocarbons and certain chemicals. As the ozone level decreases, we are in greater danger of damage by the sun.
A type of plastic that is broken down by the sun's ultraviolet rays.
To put something through a process to make it reusable or to use something again in another way. Many communities have facilities where you can recycle materials such as paper, newspaper, plastic and glass bottles, and aluminum cans. When you recycle things rather than throw them away, you produce less waste.
Replanting trees in areas where they have been cut or burned down. See also deforestation.
Energy that keeps on reproducing and never runs out, such as solar, wind, or hydroelectric energy. See also energy.
The wearing away of the soil by water, wind, waves, and glaciers. Water is responsible for two-thirds of the erosion of farmland, usually from rain, oceans, or rivers. Deforestation and planting the same crop year after year are two other causes of soil erosion. If erosion continues at the present rate, 7% of the earth's soil will be used up each decade.
Anything with poisonous ingredients. Toxic materials can cause death or injury to living creatures if not handled properly. They can be dangerous to the environment if released into the air, water, or land.