1.3. Cycles and the Earth 1. Water Cycle

Water

(1)Evaporation Heat energy from the sun causes water in puddles, streams, rivers, seas or lakes to change from a liquid to a water vapor. This is called evaporation. The vapor rises into the air and collects in clouds.  

(2)Condensation Water vapor collects in clouds. As the clouds cool the water vapor condenses into water drops. This is called condensation. These drops fall to the earth as rain, snow or hail.

(3)Precipitation Water falls to the earth from clouds. Mainly as rain, but sometimes as snow and hail. This is called precipitation.

(4)Transpiration Transpiration is the process by which plants lose water out of their leaves.  Transpiration gives evaporation a bit of a hand in getting the water vapor back up into the air.

Condensation Transpiration Precipitation Evaporation The Clouds form The movement through plants Precipitation The rain falls Evaporation The vapor rises

2. Carbon Cycle

Carbon Carbon exists in the nonliving environment as: Carbon dioxide (CO2) Carbonic acid ( HCO3−) Carbonate rocks (limestone and coral = CaCO3) Deposits of Fossil fuels Dead organic matter

Organic Carbon Hydrocarbons: CH4 Carbohydrate: CH2O

Inorganic carbon Carbon Dioxide: CO2 Calcium Carbonate: CaCO3 Mandale Limestone Quarry

Carbon reservoirs Parts of the Earth system where carbon is stored is called carbon reservoirs

Carbon is taken from the atmosphere in several ways ①Photosynthesis. ②The oceans when the seawater becomes cooler, more CO2 dissolve and become carbonic acid. In the upper ocean areas organisms convert reduced carbon to tissues, or carbonates.

Photosynthesis CO2 + H2O + sunlight  CH2O + O2

Respiration CH2O + O2  CO2 + H2O + energy

Combustion or Oxidization of hydrocarbon CH4 + 2 O2  CO2 + 2 H2O + energy

Human Impacts on the Carbon Cycle Burning fossil fuels have serious impact on the carbon cycle.

Fossil Fuel 86% of global primary energy consumption is fossil fuels.

Fossil Fuels Petroleum Natural Gas Coal

3. The Energy Cycle The amount of energy that enters the system should equal the amount that is removed. Because of the balance-scale nature of Earth’s energy cycle, scientists also call it Earth’s energy budget.

Three main sources of energy in Earth’s energy budget Solar Energy Geothermal Energy Tidal Energy

<The Law of Thermodynamics> Energy can never be created or destroyed, only changed from one form to another. When energy changes, it is converted from a more useful, more concentrated form to a less useful, less concentrated form. →Energy can never be recycled completely.