Meet the Greenhouse Gases

Greenhouse gases in our atmosphere hold on to heat. When a greenhouse gas molecule lets go of the heat, it’s caught by another greenhouse gas molecule, or it makes its way out to space.

Most of our air is nitrogen and oxygen molecules, which don’t trap heat. Only a tiny amount of our air is greenhouse gases, but they have a big impact. Greenhouse gases include water vapor, methane, ozone, nitrous oxide, and carbon dioxide. 

Some carbon dioxide (CO2) in our air is natural. Having some greenhouse gases in the air keeps the temperature warm enough for plants and animals. However, there can be too much of a good thing. People have been adding more of it to the air by burning coal, oil, and gas. This heats the Earth.

Plants use carbon dioxide and sunlight to make their own food and grow. The carbon becomes part of the plant. Plants that die and become buried may turn into fossil fuels like coal and oil over millions of years. When we burn fossil fuels, the carbon quickly gets into the atmosphere as carbon dioxide. 


Graphic showing how sunlight warms the Earth, how the heat is released from the Earth surface into the atmosphere,  how greenhouse gases hold onto the heat and vibrate. They are like a blanket in the sky. Burning fossil fiels adds more greenhouse gases to the air which makes the blanket of greenhouse gases thicker and causes climate warming.

UCAR/L.S. Gardiner