Understanding the Greenhouse Effect

The Greenhouse effect

This diagram represents the greenhouse effect.

If you haven’t studied this diagram before, you should learn its parts before taking the quizzes below.

“1” represents the sun. “2” represents the sunlight heading toward the surface of the Earth, which is shown at “3.”

Depending on conditions on the Earth’s surface, more or less of the light from the sun can be directly reflected back into space. This reflected light (what you’d see if you were standing on the moon looking at the Earth) is shown at “4.”

When light shines upon any object, some of that light gets converted into heat. Heat from the Earth is shown at “5.”

Our atmosphere (represented by “8”) is mostly nitrogen and oxygen. In addition, there are small amounts of greenhouse gases, such as carbon dioxide (CO2) and methane (CH4). In this diagram, the greenhouse gas layer is represented as number “9” and shown in green. In reality, the gases are colorless (just like oxygen and nitrogen) and they’re distributed throughout the atmosphere.

Greenhouse gases absorb the heat emitted by the Earth. Absorbing the Earth’s heat causes these molecules to vibrate. That vibration causes the molecules to re-radiate heat. Some of that heat from greenhouse gases goes into space, which is indicated by arrow “6.” The rest of the heat is sent back to Earth, indicated by arrow “7.”

The heat that’s sent back towards the Earth at “7” is the greenhouse effect. In the same way that the glass of a greenhouse lets light in but traps heat inside the greenhouse, greenhouse gases let the Sun’s light in, and trap heat inside the atmosphere. We need the greenhouse effect to keep our climate livable. If greenhouse gases fall to a very low level, Earth can get to be very cold: that’s what happens during an ice age. But if greenhouse gas levels get too high, the Earth can become much warmer. That is what is happening now, as human combustion of fossil fuels has released lots of carbon dioxide into the air in a relatively short time.

Got it?

Label the parts of the diagram below.

[qwiz random=”true”]

[h]Understanding the Greenhouse Effect (Quiz 1)

[i]

[q] In the diagram below, which number indicates the sun?

[textentry single_char=”true”]

[c*] 1

[f] Excellent. Number 1 is the sun.

[c] Enter word

[f] No.

[c] *

[f] No, but here’s a hint. The sun is shown out in space, toward the top of the diagram.

[q] In the diagram below, which number shows light from the sun moving toward the earth?

[textentry single_char=”true”]

[c*] 2

[f] Excellent. Number 2 shows light from the sun heading toward the Earth.

[c] Enter word

[f] Sorry, that’s not correct.

[c] *

[f] No, but here’s a hint. The sun is shown out in space, at number 1. What’s coming out of the sun? Find the arrow, and you’ll have your answer.

[q] In the diagram below, which number represents the surface of the Earth?

[textentry single_char=”true”]

[c*] 3

[f] Nice job. Number 3 represents the surface of the Earth.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Light from the sun (2) shines upon the Earth. Just follow the arrows shown at “2” and you’ll have your answer.

[q] In the diagram below, which number represents light from Earth that’s reflected right back into space?

[textentry single_char=”true”]

[c*] 4

[f] Terrific. Number 4 represents light from Earth reflected right back into space.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s are two hints. First, look at the legend in the top right of the diagram. Second, just note how light from the sun (2) shines upon the Earth. Find an arrow that goes from the Earth into space, and which just keeps on going.

[q] When light from the sun shines upon the Earth, some of that light gets converted into heat.  Which number represents this heat?

[textentry single_char=”true”]

[c*] 5

[f] Awesome. Number 5 represents heat that’s being emitted from the Earth. The source of that heat is light energy from the sun that’s absorbed by the Earth, and then re-emitted as heat.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s are two hints. First, look at the legend in the top right of the diagram. Second, note that light from the sun (“2”) shines upon the Earth (“3”). Some of that light gets absorbed by the Earth, and converted into heat. Which arrow, heading away from the Earth, could represent that heat?

[q] In the diagram below, which number represents heat from Earth that’s absorbed by greenhouse gas molecules and then gets re-radiated back down to the earth?

[textentry single_char=”true”]

[c*] 7

[f] Terrific. Number 7 represents heat from Earth that’s been absorbed by greenhouse gas molecules like carbon dioxide, and then gets re-radiated back down to the Earth.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Light from the sun (“2”) shines upon the Earth. Find arrows that go from the Earth and into space. However, unlike what happens at “4”, some of this energy from Earth hits something in the atmosphere, and then gets sent back down to earth? What arrow shows something being sent back down to the Earth.

[q] In the diagram below, which number represents heat from Earth that’s absorbed by greenhouse gas molecules and then gets re-radiated out into space?

[textentry single_char=”true”]

[c*] 6

[f] Terrific. Number 6 represents heat from Earth that’s been absorbed by greenhouse gas molecules like carbon dioxide, and then gets re-radiated out into space.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Find the greenhouse gas layer. Now find the arrows that are coming out of that layer. Which arrow is heading out toward space? That’s the arrow that represents the heat that you’re looking for.

[q] In the diagram below, which number represents the oxygen and nitrogen gas that makes up most of our atmosphere?

[textentry single_char=”true”]

[c*] 8

[f] Correct. Number 8 represents the gases in our atmosphere.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. The atmosphere is above the Earth’s surface (“3”), but below outer space (shown in gray). And, for this question, ignore the greenhouse gas layer.

[q] In the diagram below, only one arrow represents the warming that’s caused by the greenhouse effect. Which one?

[textentry single_char=”true”]

[c*] 7

[f] Excellent. Number “7” represents heat from the Earth that’s absorbed by greenhouse gases, and then re-radiated back to the earth. This is the energy that warms our planet, causing the greenhouse effect.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Light from the sun (“2”) shines upon the Earth. Then the Earth converts some of this light into heat. This heat hits the greenhouse gases in our atmosphere (shown at “9”). Only one arrow is moving from this arrow back down to the Earth. Find that arrow, and that’s your answer.

[q] In the diagram below, which number represents greenhouse gases?

[textentry single_char=”true”]

[c*] 9

[f] Excellent. Number “9” represents greenhouse gases such as carbon dioxide (CO2) and methane (CH4). These gases absorb the Earth’s heat, and re-radiate it in all directions. The heat that’s emitted and which comes back down to earth is shown at arrow number “7,” and that’s the greenhouse effect.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Greenhouse gases include carbon dioxide (CO2) and methane (CH4). Find these chemical formulas, and then you’ll have the greenhouse gas layer.

[x]

[restart]

[/qwiz]

Applying What You’ve Learned about the Greenhouse Effect

[qwiz random=”true”] [h]

Understanding the Greenhouse Effect (Quiz 2)

[i]

 

[q] One consequence of climate change is that ice in mountain glaciers, and at the north and south poles, is melting. Melting ice makes the surface of the Earth darker. Which arrow would become thinner as a result?

[textentry single_char=”true”]

[c*] 4

[f] Excellent. Number “4” represents light reflected from the Earth back into space. If the Earth’s ice were to melt, the Earth would reflect less, making arrow “4” thinner, with less light reflected back into space.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Light from the sun (“2”) shines upon the Earth. Find the arrow that shows light from Earth that’s reflected back into space. Think about what would happen if the Earth became darker (because of melting ice). Then you’ll have your answer.

[q] In the diagram below, which arrow would become THICKER if more ice covered the surface of the Earth, reflecting away more light?

 

[textentry single_char=”true”]

[c*] 4

[f] Excellent. Number “4” represents light reflected from the Earth back into space. If the Earth were more reflective, that arrow would be bigger.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Light from the sun (“2”) shines upon the Earth. Find the arrow that shows light from Earth that’s reflected back into space. Think about what would happen if the Earth became shinier. Then you’ll have your answer.

[q] If there were more carbon dioxide, two lines would become thicker. One of them is “6.” Which is the other one?

[textentry single_char=”true”]

[c*] 7

[f] Excellent. Number “7” represents heat that greenhouse gases are re-radiating back to Earth. If there are more greenhouse gases, then arrow “6” and arrow “7” both become thicker (meaning more heat sent back to the Earth, and more heat radiated out into space).

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Arrow “6” represents more heat radiated into space by greenhouse gases. What other arrow represents heat that’s radiated by greenhouse gases (but which is heading toward Earth instead of toward space)?

[q] If there were less carbon dioxide in the air, we could decrease the amount of heat that carbon dioxide in the air sends back to the Earth. Which arrow would become more narrow, representing a weaker greenhouse effect.

[textentry single_char=”true”]

[c*] 7

[f] Excellent. Number “7” represents heat that greenhouse gases are re-radiating back to Earth. If there were less carbon dioxide, then there would be less heat sent back to the Earth by greenhouse gases. This could be represented by a thinner arrow number 7.

[c] Enter word

[f] No, that’s not correct.

[c] *

[f] No, but here’s a hint. Which arrow represents heat that’s radiated by greenhouse gases and which heads back to Earth?

[q multiple_choice=”true”] If there were more carbon dioxide in the air, the greenhouse effect would become

[c*] stronger

[f] Yes. Carbon dioxide is a greenhouse gas. If there’s more carbon dioxide, there’s going to be a stronger greenhouse effect.

[c] weaker

[f] No. Carbon dioxide is a greenhouse gas. If there’s more carbon dioxide, what would that do to the greenhouse effect?

[c] neither weaker or stronger: it would stay the same.

[f] No. Carbon dioxide is a greenhouse gas. If there’s more carbon dioxide, what would that do to the greenhouse effect?

[q multiple_choice=”true”] If we planted trees around the world, it would absorb lots of carbon dioxide. As a result, the greenhouse effect would become.

[c] stronger

[f] No. Carbon dioxide is a greenhouse gas. If there’s less carbon dioxide, what would that do to the greenhouse effect?

[c*] weaker

[f] Yes. Carbon dioxide is a greenhouse gas. If there’s less carbon dioxide, the greenhouse effect is going to be weaker.

[c] neither weaker or stronger: it would stay the same.

[f] No. Carbon dioxide is a greenhouse gas. If there’s less carbon dioxide, what would that do to the greenhouse effect?

[q multiple_choice=”true”] If the Earth became shinier because of spreading snow and glaciers, then temperatures on our planet would probably

[c] go up

[f] No. If there’s more ice and snow, then more light gets reflected back into space (arrow “4”) above. This would decrease the amount of heat that the Earth absorbs, and it would decrease both arrows “5,” “6,” and “7.” The greenhouse effect would become weaker.  Would this make temperature go up or go down?

[c*] go down

[f] Yes. If there’s more ice and snow, then more light gets reflected back into space (arrow “4”) above. This would decrease the amount of heat that the Earth absorbs, and it would decrease both arrows “5,” “6,” and “7.” The greenhouse effect would become weaker, and Earth’s temperature would go down.

[c] stay the same

[f] No. If there’s more ice and snow, then more light gets reflected back into space (arrow “4”) above. This would decrease the amount of heat that the Earth absorbs, and it would decrease both arrows “5,” “6,” and “7.” What effect would this have on Earth’s temperature?

[x]

[restart]

[/qwiz]