Greenhouse Gases

The simplest greenhouse gas definition: Greenhouse gases (GHGs) are gases that trap heat in the Earth’s atmosphere. This is sometimes called the greenhouse effect. Some GHGs can stay in the atmosphere for thousands of years.

Examples of greenhouse gases

This list is by no means comprehensive, but each of the following is considered a greenhouse gas.

• Carbon dioxide
• Methane
• Nitrous oxide
• HVAC refrigerants
• Hydrochlorofluorocarbons (HCFCs) such as R-22
• Hydrofluorocarbons (HFCs) such as R-410A
• Hydrofluoroolefins (HFOs) such as R-454B
• Naturally occurring gases such as water vapor and ozone