Name: ______Date: ______Block:______
The Story of Earth’s Atmosphere
Learning Target: The purpose of this lesson is to visually organize and understand the atmospheric changes that occurred over Earth’s existence.
Objective: By answering the questions below, you will learn how the Earth’s atmosphere was transformed. Feel free to investigate further but keep it simple. Click on each internet link and read carefully before answering each question. You may not always need to read the whole web page to find the answer. Use [Ctrl F] to search for key words.
1. When the Earth first formed, about four and a half billion years ago, Earth's atmosphere was almost entirely made of what two elements? Why?
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2. What happened to the first gases that made up Earth’s atmosphere? Why?
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3. Soon after that, about 4.4 billion years ago, the Earth cooled down. What was occurring on Earth’s surface that contributed to the new atmosphere?
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4. What gases formed the new atmosphere?
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5. About 2.7 billion years ago, how did cyanobacteria contribute to the transformation of the atmosphere?
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6. What is another name for cyanobacteria?
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7. Millions of years later, the oxygen in the atmosphere formed a layer of ozone (O3). How is ozone effective?
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8. Prior to the formation of the ozone, life was only found where? ______
9. How was the formation of the ozone significant for life on Earth?
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10. Scientists today are able to learn about the history of the atmosphere studying stromatolites. What is a stromatolite?
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11. What is an alternate name for cyanobacteria? ______
Scroll down to the “Why are they so important?” section.
12. The stromatolites at Shark Bay are just 2,000 – 3,000 years old. What are the cyanobacteria that build them similar to?
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13. What does that mean? ______
14. What creates the Nitrogen in the Earth’s current atmosphere?
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15. What creates the Oxygen in Earth’s current atmosphere?
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16. Why is the percentage of Carbon Dioxide going up?
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17. How will the increase in Carbon Dioxide affect temperatures on Earth?
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18. What are greenhouse gases?______
19. Name the three most abundant greenhouse gases: ______
20. Climate change is happening. Our Earth is warming. Earth's average temperature has risen by 1.4°F over the past century, and is projected to rise another 2 to 11.5°F over how many years?
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21. The evidence is clear. Rising global temperatures have been accompanied by changes in weather and climate. Name three changes that places are experiencing:
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22. Describethree ways you can help stop climate change:
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