Two of the , Venus and the Earth) can experience the Greenhouse effect.

The Greenhouse effect happens when gases in trap thermal radiation from and prevent it from venting into space. The overall effect is global warming.

Carbon dioxide is the most prevalent Greenhouse gas. The planet Venus has an atmosphere dominated by carbon dioxide and the Greenhouse effect is out of control. The temperature at the surface is nearly 900 degrees Fahrenheit.

Earth also has carbon dioxide in its atmosphere; however, nothing to the degree of Venus. Carbon dioxide only makes up about 0.04 % of the atmosphere. The concern is that man-made emissions are significantly changing the percentage and will result in Greenhouse heating of the atmosphere, changing climates on a global scale.