Runaway greenhouse effect is that describes and explains the difference in the surface temperatures between the Earth and Venus. On Venus, the loss of liquid water from evaporation caused the buildup carbon dioxide. Since CO2 is a greenhouse gas, it absorbs the infrared radiation reflected from surface, which heats the atmosphere and prevents the removal of CO2. This phenomenon is caused by a high atmospheric concentration of greenhouse gases, which in turn cause overheating of the planet. The runaway effect causes an acceleration in the warming of the planet as the surface. [Journal of the Atmospheric Sciences; v59; 2801-2810; 2002.]