Energy from the sun drives Earth’s climate. Solar energy is absorbed by land, oceans, and vegetation on the Earth’s surface, the visible light is transformed into heat and re-radiates in the form of invisible infrared radiation. The climate changes when the amount of solar energy that stays in the system changes – when more heat is let into the Earth’s atmosphere or if less heat is let out of the atmosphere. If that was all there was to the story, then during the day Earth would heat up, but at night, all the accumulated energy would radiate back into space and the planet's surface temperature would fall far below zero very rapidly.

The greenhouse gases are molecules composed of more than two component atoms, bound loosely enough together to be able to vibrate with the absorption of heat. The major components of the atmosphere (N₂ and O₂) are two-atom molecules too tightly bound together to vibrate and thus they do not absorb heat and contribute to the greenhouse effect. Greenhouse gases are part of the atmospheric trace gases that comprise less than 1% of the earth's atmosphere.

There are many different factors that make climate complicated. There are probably some complications that scientists have not yet identified!  One complicating factor is how clouds affect climate change. Some types of clouds may help warming, while others may help cooling.  Atmospheric scientists are hard at work learning more about Earth’s climate.