Greenhouse Effect & Earth's Energy Balance
Change the sun, reflectivity and greenhouse gases and see the surface temperature of Earth, Venus, Mars or Snowball Earth.
Sunlight warms the Earth and the Earth sends heat back to space as infrared. Greenhouse gases absorb some of that heat and send part of it back down, warming the surface. Change the sun, the reflectivity and the greenhouse gases.
About the Greenhouse Effect & Earth's Energy Balance
Free greenhouse effect & earth's energy balance. Change the sun, reflectivity and greenhouse gases and see the surface temperature of Earth, Venus, Mars or Snowball Earth. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for earth & space, the greenhouse effect & earth's energy balance runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Change the sun, reflectivity and greenhouse gases and see the surface temperature of Earth, Venus, Mars or Snowball Earth. Use it to explore earth & space ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Greenhouse Effect & Earth's Energy Balance
- Use the controls to change Sunlight strength, Reflectivity (albedo), Greenhouse gas amount, Worlds. The simulation reacts instantly.
- Pick an option such as Earth today, No atmosphere, Snowball Earth, Venus-like to switch modes or load an example.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Choose No atmosphere and compare with Earth today.
- Raise the greenhouse gas amount a little and see how much the surface warms.
- Try Snowball Earth and explain why ice keeps a planet cold.
- Compare Venus-like and Mars-like worlds.
Key ideas you can learn
- Without any greenhouse effect Earth would average about -18 C.
- Greenhouse gases absorb heat from the ground and send part of it back down, warming the surface. The more they trap (the optical depth), the hotter it gets.
- More reflective surfaces (higher albedo) send more sunlight back to space and cool the planet.
- In balance, the heat leaving equals the sunlight absorbed.
Where this is used in the real world
Climate scientists use energy-balance models like this to understand global warming, and it also explains the surface temperatures of other planets.
Who is this simulation for?
Astronomy and earth-science students, and teachers who need a visual model to explain what is happening in the sky.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is the greenhouse effect?
A natural warming caused by gases in the air that absorb infrared heat from the surface and radiate part of it back down.
Why is Venus so hot?
It has a thick carbon dioxide atmosphere with a strong greenhouse effect and it is closer to the Sun.
Is the Greenhouse Effect & Earth's Energy Balance free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Greenhouse Effect & Earth's Energy Balance work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.