2Questions for Today:What are the four major components of Earth’s Life Support?How do scientist classify Land and Water?What are the three factors that sustain life?What happens to solar energy reaching the Earth?
3The Four SpheresEarth’s life support systems are composed of four spherical systems:AtmosphereHydrosphereGeosphereBiosphere
4The Four Spheres Atmosphere A thin spherical envelope of gases that surround the Earth’s surface.Five sections:Troposphere*Stratosphere*MesosphereThermosphereExosphere
5The Four Sphere Troposphere Extends from the surface of the earth to as high as 17 km above sea level.Contains the majority of the air we breathe.Consists mostly of:Nitrogen (78%)Oxygen (21%)The remaining one percent are composed of greenhouse gases.Water Vapor, Carbon Dioxide, and Methane.
6The Four Spheres Stratosphere Right above the Troposphere Extend from the surface km.Contains the ozone layer (O3)Ozone filters out the UV rays from the sunWithout Ozone layer, life would start to deteriorate
7The Four Spheres Hydrosphere Geosphere Biosphere Consists of all water on or near the Earth’s SurfaceCovers 71-73% of the earth’s surfaceGeosphereThe Solid EarthCore, Mantle, and CrustBiosphereAll the living aspects of the EarthExtends 9 kilometers from the surface.
8Vegetation and animals Biosphere Crust Lithosphere Mantle Biosphere AtmosphereBiosphereSoilRockCrustLithosphereMantleBiosphere(living organisms)Atmosphere(air)Figure 3.6Natural capital: general structure of the earth showing that it consists of a land sphere, air sphere, water sphere, and life sphere.CoreMantleCrust(soil and rock)Geosphere(crust, mantle, core)Hydrosphere(water)Fig. 3-6, p. 55
9Life Exists on Land and in Water Biomes are large regions on the terrestrial earth with distinct climates and certain species adapted to them.Aquatic life zones are how scientist classify the water on EarthFreshwater (2%)Marine/Ocean (71%)
10Average annual precipitation 100–125 cm (40–50 in.)75–100 cm (30–40 in.)50–75 cm (20–30 in.)25–50 cm (10–20 in.)below 25 cm (0–10 in.)DenverBaltimoreSan FranciscoSt. LouisCoastal mountainrangesSierra NevadaGreat AmericanDesertRockyMountainsGreatPlainsMississippiRiver ValleyAppalachianMountainsFigure 3.7Major biomes found along the 39th parallel across the United States. The differences reflect changes in climate, mainly differences in average annual precipitation and temperature.Coastal chaparraland scrubConiferous forestDesertConiferous forestPrairie grasslandDeciduous forestFig. 3-7, p. 55
11Life Sustaining Factors Life on Earth Depends on Three major Factors:The one way flow of high quality energyThe cycling of matter or nutrients through parts of the biosphere.Gravity
12What happens to Solar Energy Reaching the Earth The energy reaches earth in the form of EM waves.Visible Light, UV, InfraredMost of this energy is absorbed by the stratosphere or reflected back into spaceOnly 5% makes it to the surface.The energy that reaches the earth, warms the air, evaporates and cycles water.1% generates wind<0.1% is used in photosynthesis
13What happens to Solar Energy reaching the Earth 4% of the Sun’s energy is trapped within the ozone layer.This causes greenhouse gases to vibrate and release infrared radiation.The vibrating gas had high kinetic energy which warms the lower atmosphere and the surface of the earthNatural Greenhouse effect.
14What Happens to Solar Energy reaching the Earth Human Activities, such as burning fossil fuels, increase the amount of greenhouse gases in our upper atmosphere.Studies have shown that these activities are increasing the natural greenhouse effect and warming the earth’s atmosphere.
15Solar radiation Lower Stratosphere (ozone layer) Greenhouse effect Reflected byatmosphereRadiated byatmosphereas heatUV radiationLower Stratosphere(ozone layer)Mostabsorbedby ozoneTroposphereVisiblelightHeat radiatedby the earthFigure 3.8Solar capital: flow of energy to and from the earth. See an animation based on this figure at CengageNOW.HeatAbsorbedby the earthGreenhouseeffectFig. 3-8, p. 56