Skip to content
Geolens

Teachers

A lesson for your classroom or geography club

Earth’s energy budget

All teacher notes · Open the lab

Start projector

NASA CERES map of net radiation averaged over 2000–2015, with a −200 to +200 W m⁻² colour scale.
Loading photograph
NASA CERES observations, 2000–2015 mean. Net radiation is incoming sunlight minus reflected shortwave and emitted longwave energy at the top of the atmosphere. Positive values indicate a radiative surplus.

A suggested lesson sequence

Use these stages at your own pace. Pause for students to sketch, compare observations or lead part of the demonstration.

  1. 01

    Observe

    Explain why solar irradiance is divided by four. Use albedo 0.3 and turn Greenhouse off. Read the surface temperature.

    Open Observe

  2. 02

    Tinker

    Turn Greenhouse on; distinguish surface emission from outgoing radiation at the top of the atmosphere. Check the top-of-atmosphere balance.

    Open Tinker

  3. 03

    Explain

    Explain why a change in reflected sunlight or infrared absorption changes the temperature needed for energy balance.

    Open Explain

  4. 04

    Check

    Choose an answer and explain your reasoning. Each question includes feedback.

    Open Check

Rehearse with the model

The same scene and controls as the lab. Load it when you are ready; use Start projector for the full classroom view.

Before the lesson

Trace energy entering and leaving Earth, and explain how reflection and atmospheric absorption affect the surface temperature.

Open the model before the lesson and choose a view that makes the important feature easy to see. Drag to rotate, and use the on-screen controls to change one variable at a time. The Controls panel explains the available keyboard shortcuts.

Pause the animation at a useful moment. Ask students what should happen next, then play it to test their explanation.

Guide the demonstration

Explain why solar irradiance is divided by four. Use albedo 0.3 and turn Greenhouse off. Read the surface temperature.

Turn Greenhouse on; distinguish surface emission from outgoing radiation at the top of the atmosphere. Check the top-of-atmosphere balance.

Discuss a common misconception

“Greenhouse gases mainly warm Earth by trapping incoming visible sunlight.” Much incoming solar radiation reaches the surface, where some is absorbed. The warmed surface emits thermal infrared radiation, which greenhouse gases and clouds absorb and emit. This exchange changes the surface temperature needed for the Earth system to balance absorbed solar energy with energy leaving for space.

Build the explanation

Earth reflects some incoming sunlight and absorbs the rest. Its temperature adjusts as outgoing thermal radiation balances absorbed energy; greenhouse gases change the exchange of thermal radiation.

Turn Greenhouse on; distinguish surface emission from outgoing radiation at the top of the atmosphere. Check the top-of-atmosphere balance.

This simple energy-balance model isolates selected processes rather than representing the full atmosphere and climate system.

Teaching notes

Distinguish the model’s energy transfers from a prediction of future climate.

Explain albedo as the fraction of incoming sunlight reflected, and distinguish shortwave sunlight from outgoing longwave radiation.

Use only the energy values supplied by the model when comparing transfers or checking a budget.

Check understanding

Open Check for 4 questions. Ask students to explain their choice before revealing the answer.

Return to the opening photograph. Ask students to identify one visible feature and explain which part of the model helps account for it.

Look more closely

Use these observations to connect the vocabulary to features students can identify.

Albedo

NASA CERES map of reflected shortwave radiation averaged over 2000–2015, with a 0–385 W m⁻² colour scale.
Loading photograph
CERES measures reflected shortwave energy in W m⁻². Albedo is the fraction of incoming sunlight reflected, so obtaining it requires dividing reflected flux by the corresponding incoming flux; the colour scale here is not albedo.
Read the definition

Longwave

CERES global map of outgoing longwave radiation with a colour scale in watts per square metre.
Loading photograph
NASA CERES, April 2015. Satellite observations map outgoing thermal radiation at the top of the atmosphere in W m⁻²; colder cloud tops generally emit less than warm clear-sky regions.
Read the definition

Sources to keep beside the lesson

Watch an explanation

Loading video player

The film stays paused until you play it.

What Does the Atmosphere Do? Crash Course Geography #6 Crash Course

Same realm