The greenhouse effect is a natural process that warms the Earth’s surface by trapping heat in the lower atmosphere. When sunlight reaches the Earth, it passes through the atmosphere and warms the planet’s surface. The Earth’s surface then emits heat in the form of infrared radiation. Greenhouse gases such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapor, and ozone absorb some of this infrared radiation and re-emit it in all directions, including back toward the surface. This trapping of heat keeps Earth’s average temperature at around 15°C (59°F), making it habitable. However, human activities—primarily the burning of fossil fuels and deforestation—have increased the concentration of greenhouse gases, enhancing the natural greenhouse effect. This intensified effect traps more heat, leading to global warming and climate changes. Without the greenhouse effect, Earth’s average surface temperature would be about -18°C (0°F), but the enhanced greenhouse effect caused by anthropogenic emissions has already caused an increase of roughly 1.2°C since the industrial era. This warming disrupts climate patterns and contributes to more extreme weather, rising sea levels, and ecological impacts.
Back to Climate Change Encyclopedia Index Page