What's Up with Water?

When it comes to greenhouse gases, many people talk about carbon dioxide. But, have you ever heard anyone mention water? Water—in the form of water vapor—is actually Earth’s most abundant greenhouse gas.
Water vapor amplifies the problems caused by greenhouse gases. The warmer the Earth gets, the more water in the air, and the warmer the planet will get. It’s a vicious cycle…and there’s very little we can do to change the amount of water in the atmosphere.
WATER AS CLOUDS: Almost no water is stored in the atmosphere; it just continues to change forms. The tiny amount of water in the air forms clouds, makes rain, and is an important part of our weather.

WATER AS HUMIDITY: Near the ground, the amount of water in the air is called humidity. When there’s lots of humidity, you are more likely to see rain, fog, and dew.

WATER AS ICE: When water vapor is in a solid form, we see it as snow or ice. At certain temperatures, it can melt into water or even evaporate directly into water vapor.