The Atmosphereand theEnvironment
Gasses in the Atmosphere
Earth’s atmosphere is made up ofNITROGEN, oxygen, carbon dioxide, watervapor, and many other gases, as well asparticles of liquids and solids.
Layers of the Atmosphere
As altitude increases, the temperature andpressure decrease.
Scientists divide Earth’s atmosphere intofour main layers classified according tochanges in temperature. These layers arethe troposphere, the stratosphere, themesosphere, and the thermosphere.
Layers
Troposphere -is the layer of the atmosphere in whichEarth’s weather occurs.
Stratosphere -is the second layer of the atmosphere andcontains the ozone layer.
Mesosphere -is the layer of the atmosphere that protectsEarth’s surface from being hit by most meteoroids.
Thermosphere -the outmost layer of Earth’s atmosphereis the
The lower layer, called the ionosphere, contains the auroraborealis
The outer layer of the thermosphere is the exosphere.
Temperature and Pressure
As altitude increases
air pressure and temperature decrease.
Sources of Pollution in theAtmosphere
NATURAL PROCESSES
Many natural processes add particles to theatmosphere.
Forest fires, soil erosion, and dust storms releasea great deal of smoke and dust into the air.
The wind carries particles of molds and pollen.
Erupting volcanoes spew out clouds of dust andash along with poisonous gases.
Sources of Pollution in theAtmosphere
Human Activities
Human activities, such as farming andconstruction, can send soil and dust into the air.
But most air pollution is the result of burningfossil fuels, such as coal, oil, gasoline, anddiesel fuel.
Almost half of this pollution comes from cars andother motor vehicles. Factories and power plantsthat burn coal and oil also release pollution.
Particles in the Environment
Pollutants are harmful substances in theair, water, or soil. Air that contains harmfulparticles and gases is said to be polluted.Air pollution can affect the health ofhumans and other living things.
High levels of air pollution decrease thequality of the air. The burning of fossil fuelscan cause smog and acid rain by leavingparticles in the air.
Acid Rain
Rain is naturally slightly acidic, but rain thatcontains more acid than normal is called acid rain.
Where does acid rain come from? The burning ofcoal that contains a lot of sulfur produces sulfuroxides, substances composed of oxygen andsulfur
Acid rain is sometimes strong enough to damagethe surfaces of buildings and statues. It alsoharms lakes and ponds. Acid rain can make waterso acidic that plants, amphibians, fish, and insectscan no longer survive in it.
Photochemical Smog
A brownish haze that is a mixture of ozoneand other chemicals, formed whenpollutants react with each other in thepresence of sunlight.