This describes and explains the difference in the surface temperatures between the Earth (average surface temperature 15 C) and Venus (450 C). Note that Venus is not this temperature because of its proximity to the sun. This phenomenon on Venus is caused by a high atmospheric concentration of greenhouse gases, which in turn cause overheating of the planet. The runaway effect causes a permanence in the warming of the planet at the surface. On Venus, the loss of liquid water from evaporation and subsequent photolysis of H₂O and loss of atomic H to space in the planet's early life caused the buildup of carbon dioxide in Venus' atmosphere. Since CO₂ is a greenhouse gas, it absorbs the infrared radiation reflected from the planet's surface, which heats the atmosphere and prevents the removal of CO₂ by rain out and depositional processes that capture CO₂ as carbonates.