Energy constantly travels from the Sun to the Earth and from the Earth to the Sun. But, when something gets in the way, it can make a big difference. Explore to see how energy from the sun - and the warmth it brings - travels.

Nitrogen (N2) makes up about 78% of the molecules in Earth's atmosphere. It is not a greenhouse gas (GHG). Why do you think nitrogen isn't a GHG?

Carbon dioxide (CO2) is considered a greenhouse gas. There is very little carbon dioxide in our atmosphere (0.04%). But it makes up 63% of the greenhouse gases that are blanketing the Earth. Can you figure out why carbon dioxide is a GHG?