The Greenhouse Effect

Infrared, CO₂ and warming

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• The Sun shines in visible light. Earth glows in infrared (about 10 µm).
• Water vapour and CO₂ absorb infrared, warming the surface by about 33 °C.
• CO₂ forcing $\approx 5.35\ln(C/C_0)$ W/m²: about 3.7 W/m² per doubling.

Steps

1. Two kinds of light
2. Earth’s glow
3. Not like a real greenhouse
4. Adding CO₂
5. One blanket of air
6. Forcing so far