There is a natural cycle of gases and matter transferring between land, water, and the atmosphere driven by processes like photosynthesis, respiration, decomposition, fire, digestion, evaporation, etc. Some gases that enter into our atmosphere are critical for maintaining the planet at a livable temperature. Acting collectively as a greenhouse for Earth, these 'greenhouse gases' are heated by the sun and maintain temperatures on the surface of the planet. Water vapor, carbon dioxide, methane, and nitrous oxide are all naturally occurring greenhouse gases.

One of the greenhouse gases we hear a lot about is carbon dioxide. Carbon is everywhere and it's not a bad thing. We are made of carbon. So are trees and rocks and animals - living and dead. Carbon normally cycles through water and the atmosphere as illustrated in the diagram below. A lot of carbon gets stored or sequestered in the ground or at the bottom of lakes or ocean when plants and animals die. Part of the challenge with our climate right now is that we have been digging up fossil fuels (made of dead dinosaurs and plants) and burning them for energy. This is adding more carbon to the atmosphere than is getting stored, and the greenhouse is getting too warm!