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Climate Expedition

Lesson 3: The Carbon Cycle

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The�Greenhouse Effect

Good or Bad for Earth? Why?

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Atmosphere = Greenhouse Glass

Reminder

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Positive Feedback Loop

Reminder

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Q: What makes �Atmospheres Thick?

Venus used to have life and water, but volcanoes made the "greenhouse glass" thicker. What did volcanos pour into the air in Venus?

?

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Carbon?

Carbon is the basis of all life on earth. It is in everything. It is neither created nor destroyed, just changes form and location.

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Is Carbon a gas?

There sure is a lot of carbon in the air today, Johnny!

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Carbon Dioxide is a gas!

What do we know about Carbon Dioxide?

Say a CO2 fact about one of these?

​

  1. Soda
  2. Rock Concerts & Movie Mist
  3. Human Beings
  4. NOT Cars
  5. Fires
  6. Asphyxiation
  7. Swiss Cheese

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Q: Why isn't Earth like Venus?

How come we don't have a "positive feedback loop" that makes it too hot to live here?

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Plants Eat the CO2

They pull CO2 from the air, store the C and release the O.�So plants are mostly Carbon.�Vocab: "Carbon Sink".

"Sink" for CO2

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Photosynthesis

1 Carbon atom plus 2 Oxygen atoms = 1 CO2 molecule.�Plants use the sun's energy to break CO2 apart and eat the carbon. �We get the Oxygen.

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Humans Make CO2

What do we do that puts CO2 back in the atmosphere?

Where does it come from, besides our breathing?�Vocab: "Carbon Source".

"Source" of CO2

oil and coal

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Adding "Glass"

Here are some ways we increase greenhouse gases in the atmosphere.

Human Sources of �Greenhouse "Glass"

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Which gas makes the "Greenhouse Glass" thickest?

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Which Gas is Worse?

If you wanted to keep Greenhouse Glass from getting thicker, what gas should we focus on most?

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Biggest impact is from Oil & Coal. �It would have been CFCs but we stopped in the 1990s!

Why can't we do that with coal, oil & gas?

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Which are CO2 sources? Which are sinks?

oil and coal

oil and coal

https://lucid.app, 2WA UZG

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"Sink" for CO2

Sinks�for CO2

"Sink" for CO2

Sources for CO2

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For a Stable System:

CO2sources and sinks must stay in balance. That means don't:

  1. Cut down the trees
  2. Poison the ocean
  3. Pump much CO2 into the air than plants can eat.

oil and coal

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TPS: How is there CO2 balance in the winter?

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Students said:

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Answer:

There isn't balance. The amount of CO2 rises and falls with the seasons.

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But it averages out.

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Vocab: Average line