What is the greenhouse effect?

The greenhouse effect occurs when greenhouse gases (GHGs) accumulate in the Earth's atmosphere. These naturally occurring gases include carbon dioxide (CO₂), methane (CH₄), nitrogen oxide (N₂O), and fluorinated gases (HFCs), chlorofluorocarbons (CFCs).

Greenhouse gases trap the sun's heat as it reflects from the Earth's surface. This process warms the planet and leads to rising global temperatures. Without the natural greenhouse effect, the global mean temperature would be -18°C and therefore uninhabitable for humans. Humans amplify the natural greenhouse effect by releasing greenhouse gases when burning fossil fuels such as coal, oil, and natural gas.