The greenhouse effect

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Energy flows as a share of incoming sunlight (NASA)

   Flow	Share of incoming sunlight
   Reflected to space	29%
   Absorbed by the atmosphere	23%
   Absorbed by the surface	48%
   Infrared up from the surface	117%
   Infrared back down to the surface	100%
   Infrared from the surface straight to space	12%
   Infrared from the atmosphere to space	59%

2. 1.

   Using the table, the surface sends up 117% and gets 100% back. What is the net upward infrared, by Bo's math (NASA)?

   • 17% of incoming sunlight
   • 1.17% of incoming sunlight
   • 59% of incoming sunlight
   • 217% of incoming sunlight
3. 2.

   Of a net 17% leaving the surface as infrared, about 12% escapes straight to space. How much is absorbed by the air, by Esme's math (NASA)?

   • About 29%
   • About 1.4%
   • About 5%
   • About 71%
4. 3.

   Using the table, about 12% escapes straight to space and 59% leaves from the atmosphere. What is the total leaving as infrared, by Jun's math?

   • About 117%
   • About 47%
   • About 29%
   • About 71%
5. 4.

   Sunlight arrows in, and infrared arrows going up, back down and out to space. Why is the surface warmer than sunlight alone would make it, by Luz's reading (NASA)?

   • The ground makes its own extra heat each day
   • Back radiation from the atmosphere adds heat
   • The air keeps sunlight from leaving again
   • Reflected sunlight lands twice on the ground

6. Use this

   Absorption bands for water vapor and CO₂, with a window near 10 micrometers.

7. 5.

   NASA: water vapor lets some infrared through a window. Around what wavelength is that window centered, by Noah's reading?

   • About 1 micrometer
   • About 10 micrometers
   • About 0.5 micrometers
   • About 100 micrometers
8. 6.

   NASA: CO₂ strongly absorbs infrared longer than about 12 to 13 micrometers. What does more CO₂ do to the window, by Pia's reading?

   • Blocks more sunlight from coming in
   • Partly closes it, so less heat escapes
   • Opens it wider, so more heat escapes
   • Leaves it unchanged, since water vapor controls it
9. 7.

   Why does adding CO₂ matter even though water vapor is the most abundant greenhouse gas, by Ren's reading (NASA)?

   • CO₂ absorbs the same wavelengths, so it adds little
   • Water vapor does not absorb any infrared
   • CO₂ absorbs wavelengths that water vapor lets through
   • CO₂ reflects incoming sunlight back to space

10. Table, Greenhouse gas levels (IPCC AR6; NOAA), with columns Gas, Level

    Carbon dioxide (CO₂), 2019, 410 ppm; Carbon dioxide, before about 1750, 280 ppm or less; Methane (CH₄), 2019, 1866 ppb; Nitrous oxide (N₂O), 2019, 332 ppb.

11. 8.

    Using the table, how much higher was CO₂ in 2019 than before about 1750, by Tala's math?

    • About 130 ppm
    • About 690 ppm
    • About 1.5 ppm
    • About 1,456 ppm
12. 9.

    Using the table, the 2019 CO₂ level is about how many times the level before about 1750, by Zee's math?

    • About 15 times
    • About 1.5 times
    • About 0.7 times
    • About 130 times
13. 10.

    Which two gases in the table are given in parts per billion, by Ari's reading?

    • Methane and nitrous oxide
    • Oxygen and nitrogen
    • Carbon dioxide and nitrous oxide
    • Carbon dioxide and methane