The greenhouse effect is a natural process where atmospheric gases trap heat – a phenomena that allows the Earth to retain enough solar heat to be livable. Without the greenhouse effect, the Earth would not support most forms of life.
Although the process is complex, the greenhouse effect can be described fairly simply:
Sunlight passes through the atmosphere. Clouds, ice caps and other light-colored surfaces reflect some light back into space, but most of the incoming energy reaches the planet’s surface. The Earth radiates heat back toward space. Greenhouse gases in the atmosphere absorb that heat, bouncing some back to the Earth’s surface and releasing some into the atmosphere.
Greenhouse gases include carbon dioxide, methane, nitrous oxide and other gases that accumulate in the atmosphere and create the heat-reflective layer that keeps the Earth at a livable temperature. These gases form the insulation that keeps the planet warm enough to support life.
Some of the most common — and worrisome — greenhouse gases are:
Modern climate change is caused by an excess of greenhouse gases. This, in turn, over-insulates the planet. As a result, temperatures rise. Imagine wearing a winter parka in the tropics. The effect is similar — too much insulation causes the planet to overheat, which has already begun to change the climate. Learn more about the impacts of climate change.