What Causes a ‘Greenhouse Effect’ on Earth?

Imagine Earth as a cozy house with windows. The sun sends heat inside, but when the windows are closed, the heat stays in, just like a hot tub keeps you warm. That’s what happens in the greenhouse effect: gases in the air act like windows that trap the sun's warmth and keep Earth comfortable.

The sun shines on Earth, warming it up. Some of the heat goes back into space, but certain gases, like carbon dioxide and methane, catch some of that heat and hold it close to Earth, making our planet stay warm.