How does the greenhouse effect work?
As you might expect from the name, the greenhouse effect works … like a greenhouse! A greenhouse is a building with glass walls and a glass roof. Greenhouses are used to grow plants, such as tomatoes and tropical flowers.
A greenhouse stays warm inside, even during the winter. In the daytime, sunlight shines into the greenhouse and warms the plants and air inside. At nighttime, it’s colder outside, but the greenhouse stays pretty warm inside. That’s because the glass walls of the greenhouse trap the Sun’s heat.
A greenhouse captures heat from the Sun during the day. Its glass walls trap the Sun’s heat, which keeps plants inside the greenhouse warm — even on cold nights. Credit: NASA/JPL-Caltech
The greenhouse effect works much the same way on Earth. Gases in the atmosphere, such as carbon dioxide, trap heat just like the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.
During the day, the Sun shines through the atmosphere. Earth’s surface warms up in the sunlight. At night, Earth’s surface cools, releasing heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. That’s what