This document provides an introduction to environmental science, describing the unique characteristics of planet Earth that enable life. It discusses the lithosphere, hydrosphere, atmosphere, and biosphere. The lithosphere contains three main rock types and the hydrosphere is made up mostly of oceans. The atmosphere protects life from radiation and is composed primarily of nitrogen and oxygen. It also contains four layers, including the troposphere where weather occurs. Finally, the biosphere encompasses all life on Earth across the other spheres in a complex network of interactions.

1. Welcome to Environmental Science! What do you think of when you hear “environmental science”?? Make a list of anything that comes to mind.

4. 1.1 Cont. Organism – any living thing To have life: need just the right mix of materials, like carbon, oxygen, water, etc. need the right temperatures for life, most other planets are too hot or too cold. need an atmosphere that would protect any life from the sun’s radiation. So what characteristics does Earth have?

5. On Earth: liquid water – stores and then releases heat, keeping temperatures steadier. Atmosphere supports life – nitrogen, oxygen, CO2. Energy comes from the sun and travels in wavelengths Visible Spectrum is very small = ROYGBIV Ozone Layer protects us from the sun’s radiation. Life is found on the ground, in the air, and in the water. 1.1 Cont.

6. 1.1 Cont. Lithosphere– the layer of land that forms the Earth’s surface Hydrosphere– all parts of the Earth made of water (oceans, lakes, rivers, underground, clouds) Atmosphere– the layer of air that surrounds the Earth Ecology – interactions between the living & nonliving parts of earth

7. 1.2 Earth’s Land & Water Lithosphere: 10-200km thick 3 main types of rocks Igneous: formed by the cooling of liquid rock (ex. Granite) Sedimentary: layers of sediments compressed (ex. Sandstone) Metamorphic: rock transformed by heat and pressure (ex. Marble and Slate)

8. 1.2 Cont. Hydrosphere: 70% of Earth’s surface = water 97% of that is salt water Fresh water: Surface water: lakes, streams Groundwater: underground, moves between rocks 2/3 of fresh water is frozen in glaciers and ice caps

9. 1.2 Cont. Hydrosphere Cont.: Aquifer = underground layer of porous rock that contains water. Replenishes slowly Artesian well = well where water flows to surface because high underground pressure We pump water out of aquifers faster than it can be replenished, many are drying up.

10. Think About It: Water, like all liquids, expands when it is heated. Many scientists are worried about the temperatures of Earth rising. Please answer the following questions & turn them in. 1. If the temperature of Earth’s oceans were to rise, what would happen to the size of the oceans? 2. What might happen to the land along the coasts of the continents?

11. 1.2 Cont. Remember: What is a hypothesis? Hypothesis – possible explanation for a set of observations Set-up atmosphere activity

12. 1.3 The Atmosphere Atmosphere: Envelope of gases surrounding Earth What do you think it is made up of? Nitrogen = 78%, Oxygen = 21%, Carbon Dioxide = 0.04%, other matter = 0.06% (water vapor, dust particles, small amount of other gases) Why is CO2 important? Plants need it for photosynthesis to make O2

13. 1.3 Cont. 4 Layers: Thermosphere (>85km) Mesosphere (50-85km) Stratosphere (18-50km) Troposphere (8-18km)

14. 1.3 Cont.

15. 1.3 Cont. Troposphere – touches surface of Earth. Contains most of the water vapor in atmosphere. Where most of weather occurs Winds are important factor in climates. Wind patterns are caused by rotation of the earth (pg. 10)

17. 1.3 Cont. Stratosphere Contains ozone layer = form of oxygen gas containing 3 oxygen atoms per molecule. (in troposphere O2) Ozone layer filters most ultraviolet radiation, which would destroy much of the life on Earth. Mesosphere Coldest layer of atmosphere, as low as -100C

18. 1.3 Cont. Thermosphere Outermost layer, higher temps, as high as 2000C, air pressure very low. Gas molecules in one part of thermosphere are bombarded with rays from sun, cause gas molecules to lose electrons, becoming ions. Therefore called ionosphere. When gas molecules interact with free electrons light is given off. Usually occurs near poles and results in light displays called an aurora.

19. 1.3 Cont.

20. 1.4 The Biosphere Biosphere – all the parts of the earth that support and contain life About 20 km thick Most life is between 500m below sea level – 6km above sea level Organisms find energy they need in many different parts of biosphere. Ex. Humans live on lithosphere, drink water from hydrosphere & breathe from atmosphere

21. 1.4 Cont. Changes in environment can effect organisms and organisms can cause changes in environment. Biosphere is a complex network of interactions.