Global Global Changes in Changes in the the AtmosphereAtmosphere

Global WarmingGlobal Warming Global Warming- the gradual increase in the

temperature of `Earth’s atmosphere

Greenhouse Effect-◦Greenhouse Effect- the ability for gases to hold in

heat and keep the atmosphere warm◦Greenhouse Gases- Water Vapor & Carbon Dioxide◦Human activities that add greenhouse gases to the

atmosphere may be warming Earth’s atmosphere ◦Burning of wood, coal, oil and natural gases add

CO2

Global WarmingGlobal WarmingAnother Hypothesis◦Natural climate variations (a natural cycle caused by changes in solar output)

Possible Effects◦Longer growing seasons◦More evaporation drying out soil-> dust bowls

◦More storms◦Rising sea levels due to ice caps melting-> flooding

Ozone DepletionOzone DepletionChemicals produced by humans have

been damaging the ozone layerChlorofluorocarbons (CFCs)- complex

chlorine compounds found to destroy ozone molecules◦Found in air conditioner and refrigerator coolants, some cleaners and spray cans

◦In the late 1970’s the U.S. banned the use of CFCs in spray cans

◦Effects->more UV rays reaching the surface and causing more eye and skin damage