Earth’s Energy Balance

In the picture

1. 1Badge 1 sits on the Sun, the source of incoming solar radiation.
2. 2Badge 2 sits on a cloud top where some shortwave sunlight is reflected away.
3. 3Badge 3 sits on a greenhouse gas molecule in the atmosphere.
4. 4Badge 4 sits where infrared radiation leaves Earth’s surface.
5. 5Badge 5 sits on an infrared ray bending back toward Earth after interacting with a greenhouse gas molecule.

Examples

• A car interior warms in sunlight because visible light enters and infrared struggles to escape.
• A blanket traps body heat, similar to how greenhouse gases slow Earth’s heat loss.

Quiz: Earth’s Energy Balance (Age 16)

1. 1

   In Earth’s energy budget, how does radiation arrive at the planet and how does it leave?

   • It arrives as shortwave solar radiation and leaves as infrared radiation.
   • It arrives and leaves only as shortwave solar radiation.
   • It arrives as infrared radiation and leaves as shortwave solar radiation.
2. 2

   What is the greenhouse effect’s main role in Earth’s energy balance?

   • Greenhouse gases prevent infrared from being produced at Earth’s surface.
   • Greenhouse gases absorb some outgoing infrared and send part back toward the surface.
   • Greenhouse gases reflect all incoming sunlight before it can warm the surface.
3. 3

   What does it mean for Earth’s energy budget to be balanced?

   • Earth returns more energy than it receives, so it cools forever.
   • Earth absorbs more energy than it returns, so it warms forever.
   • The energy arriving from the Sun is matched by the energy Earth returns to space.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.