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Global Changes in the Global Changes in the AtmosphereAtmosphere

Global WarmingGlobal Warmingandand

Ozone DepletionOzone Depletion

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Global WarmingGlobal Warming

• Over the last 120 years , the average Over the last 120 years , the average temperature of the troposphere( the temperature of the troposphere( the layer of the atmosphere closest to layer of the atmosphere closest to Earth) has risen by 0.5Earth) has risen by 0.5° Celsius° Celsius

• Global WarmingGlobal Warming is the gradual increase in is the gradual increase in the temperature of Earth’s atmospherethe temperature of Earth’s atmosphere

• The Greenhouse EffectThe Greenhouse Effect is a natural process is a natural process by which heat is trapped in the atmosphere by which heat is trapped in the atmosphere by water vapor, carbon dioxide, methane and by water vapor, carbon dioxide, methane and other gases that form a “blanket” around the other gases that form a “blanket” around the Earth.Earth.

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Global WarmingGlobal Warming

• The gases that trap solar energy are called The gases that trap solar energy are called greenhouse gases. greenhouse gases. The greenhouse The greenhouse effect helps life to exist on Earth.effect helps life to exist on Earth.

• Human activities that add Human activities that add greenhouse gases to the atmosphere greenhouse gases to the atmosphere may be warming Earth’s atmosphere.may be warming Earth’s atmosphere.

• Burning wood, coal, oil, and natural Burning wood, coal, oil, and natural gas adds carbon dioxide to the gas adds carbon dioxide to the atmosphere.atmosphere.

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Ozone DepletionOzone Depletion

• Ozone is a gas in the stratosphere, a Ozone is a gas in the stratosphere, a high layer of the atmosphere, that high layer of the atmosphere, that absorbs most of the ultraviolet radiation absorbs most of the ultraviolet radiation that strikes Earth from the sun.that strikes Earth from the sun.

• Chemicals produced by humans Chemicals produced by humans have been damaging the ozone have been damaging the ozone layer, chloroflourocarbons (CFC’s) layer, chloroflourocarbons (CFC’s) are the main causeare the main cause

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Ozone DepletionOzone Depletion

• A decrease of ozone in the A decrease of ozone in the stratosphere means more ultraviolet stratosphere means more ultraviolet radiation strikes Earth’s surface, and radiation strikes Earth’s surface, and us. Ultraviolet radiation can causeus. Ultraviolet radiation can cause

- sunburns- sunburns

-eye damage-eye damage

- skin cancer- skin cancer

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Melting Glaciers/ Ice CapsMelting Glaciers/ Ice Caps

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Melting Glaciers/ Ice CapsMelting Glaciers/ Ice Caps

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