The greenhouse effect
Watch sunlight come in and infrared heat try to leave. Change the carbon dioxide and hold the planet at a target temperature.
Tap the air to add carbon dioxide. Tap a molecule to take it away.
What to notice
Follow one infrared photon up from the warm ground. When it reaches carbon dioxide, the molecule shakes and sends it off in a new direction, often back down. Nitrogen and oxygen let it pass.
Key numbers
| 1850 | 280 ppm | 13.9 °C | |
|---|---|---|---|
| Today | 420 ppm | Try it | |
| Doubled | 560 ppm | Try it |
What students walk away with
- 1Sunlight warms the ground, and the ground sheds that heat as infrared light.
- 2Carbon dioxide absorbs infrared and sends some of it back down. Nitrogen and oxygen let it pass.
- 3More carbon dioxide means a warmer planet, and the temperature takes years to catch up.
Standards
- MS-ESS3-5 Causes of rising global temperatures
- HS-ESS2-4 Energy flow and changes in climate
Grades 6 to 12. Question sets for middle school, high school, and upper high school.
How the model works
The planet is a one-box energy balance: sunlight in is fixed, and carbon dioxide slows the infrared leaving, with 3 °C of warming per doubling of carbon dioxide at balance.
Only the fast upper ocean stores heat here, so the planet settles in about ten model years; the real deep ocean keeps the warming going for centuries.
The photons are a sample, not a count, and water vapor and clouds are held fixed. No greenhouse gases is a separate switch because the carbon dioxide law breaks down near zero.
Run it with a class
Pick the questions, get a class code, and watch answers arrive live. Students need only a first name.
Set up an assignment