While Earth’s atmosphere has only about 0.04% carbon dioxide, Venus has an incredibly thick atmosphere dominated by the gas. This density creates a surface pressure 92 times that of Earth. The carbon dioxide allows solar energy to enter but prevents almost all infrared heat from escaping. This results in a uniform temperature across the planet, day or night. For Earth, Venus serves as a laboratory for atmospheric physics, demonstrating the potent power of carbon dioxide to regulate—or in this case, overheat—a planetary body through the radiative forcing of the greenhouse effect.