What traps the heat next to the Earth?
The atmosphere acts as a blanket that traps heat next to Earth. The atmospheric “blanket” includes a mixture of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. These gases trap heat in the lower atmosphere that is trying to escape. As the Sun’s rays enter Earth and strike its surface, the rays are reflected back upwards. Although some of this energy is lost back to space, the atmosphere will ricochet some of the rays back the Earth’s surface again. In this way, heat is retained on Earth.
Additionally, the Earth’s atmosphere acts like a shield that prevents Earth from harmful radiation.
According to the National Oceanic and Atmospheric Administration, Earth emits about seventy percent of the incoming energy back to space as heat or infrared radiation. Thus, the temperature on Earth does not become too hot.
The relatively mild temperature range and the protection of Earth from harmful radiation due to this atmospheric blanket are two qualities that make Earth suitable for living things.