1. Water Cycle Evaporation – fresh water evaporates from bodies of water Precipitation – the vaporized water cools and falls Transpiration – water evaporates from plants – Human Activity Ground water mining – as a result the residents in that area run out of water, especially for farming Pollution of freshwater Aquifer – rock layer that contain water and release it into wells or springs

2. Carbon Cycle Cellular Respiration – animals and nonplants breathe in oxygen and release carbon dioxide Decomposition – bodies of living organisms decompose and release carbon dioxide Carbonification – decomposed remains fossilize under pressure (where we get the fossil fuels we burn) Photosynthesis – plants take up carbon dioxide from the air and incorporate carbon into organic nutrients that are food for other living things – Human Activity Combustion of Fossil Fuels – increases the CO 2 in the atmosphere  worsens the greenhouse effect Deforestation – less trees  more carbon in atmosphere

3. Nitrogen Cycle Nitrogen Fixation – bacteria convert nitrogen gas (N 2 ) into a useable form Consumption – consumers eat the converted nitrogen Dentrification – bacteria put nitrogen back into the atmosphere – Human Activity: fertilizer production (contains nitrogen) is used on farms and even outside homes Run-off – fertilizer contaminates the water and leads to an algae bloom (eutrophication – algae take up all the oxygen so other organisms cannot survive)