1. The Atmosphere and the Environment

2. Gasses in the Atmosphere Earth’s atmosphere is made up of NITROGEN, oxygen, carbon dioxide, water vapor, and many other gases, as well as particles of liquids and solids. PERCENTAGE PIE GRAPH

3. Layers of the Atmosphere LAYERS OF THE ATMOSPHERE As altitude increases, the temperature and pressure decrease. Scientists divide Earth’s atmosphere into four main layers classified according to changes in temperature. These layers are the troposphere, the stratosphere, the mesosphere, and the thermosphere.

4. Layers Troposphere -is the layer of the atmosphere in which Earth’s weather occurs. Stratosphere -is the second layer of the atmosphere and contains the ozone layer. Mesosphere -is the layer of the atmosphere that protects Earth’s surface from being hit by most meteoroids. Thermosphere -the outmost layer of Earth’s atmosphere is the The lower layer, called the ionosphere, contains the aurora borealis The outer layer of the thermosphere is the exosphere.

5. Temperature and Pressure Layers and Temperature As altitude increases air pressure and temperature decrease.

6. Sources of Pollution in the Atmosphere NATURAL PROCESSES Many natural processes add particles to the atmosphere. Forest fires, soil erosion, and dust storms release a great deal of smoke and dust into the air. The wind carries particles of molds and pollen. Erupting volcanoes spew out clouds of dust and ash along with poisonous gases.

7. Sources of Pollution in the Atmosphere Human Activities Human activities, such as farming and construction, can send soil and dust into the air. But most air pollution is the result of burning fossil fuels, such as coal, oil, gasoline, and diesel fuel. Almost half of this pollution comes from cars and other motor vehicles. Factories and power plants that burn coal and oil also release pollution.

8. Particles in the Environment Pollutants are harmful substances in the air, water, or soil. Air that contains harmful particles and gases is said to be polluted. Air pollution can affect the health of humans and other living things. High levels of air pollution decrease the quality of the air. The burning of fossil fuels can cause smog and acid rain by leaving particles in the air.

9. Acid Rain Rain is naturally slightly acidic, but rain that contains more acid than normal is called acid rain. Where does acid rain come from? The burning of coal that contains a lot of sulfur produces sulfur oxides, substances composed of oxygen and sulfur Acid rain is sometimes strong enough to damage the surfaces of buildings and statues. It also harms lakes and ponds. Acid rain can make water so acidic that plants, amphibians, fish, and insects can no longer survive in it.

10. Photochemical Smog A brownish haze that is a mixture of ozone and other chemicals, formed when pollutants react with each other in the presence of sunlight.