The sun is the Earth’s primary energy source, a burning star so hot that we can feel its heat from over 150 million kilometers away.
About one third of this solar energy is reflected back into the universe by shimmering glaciers, water and other bright surfaces. Two thirds, however, is absorbed by the Earth, thus warming land, oceans, and the atmosphere.
Much of this heat radiates back out into space, but some of it is stored in the atmosphere. This process is called the greenhouse effect. Without it, the Earth’s average temperature would be a chilly -18 degrees Celsius, despite the sun’s constant energy supply.
In a world like this, life on Earth would probably have never emerged from the sea. Thanks to the greenhouse effect, however, we enjoy a comfortable average temperature of 14 degrees Celsius.
So, how does it work?