Only Venus and Earth have a greenhouse effect because they have a substantial atmosphere. Venus actually has a runaway greenhouse effect causing its surface temperatures to rise to 450 Celsius.
The inner planet that has an atmosphere containing mostly carbon dioxide is Venus. It has an extremely dense atmosphere, made up mostly of carbon dioxide with small amounts of nitrogen and trace amounts of other gases. The thick atmosphere contributes to Venus' extreme greenhouse effect, making it the hottest planet in the solar system.
Venus is the hottest inner planet because of its thick atmosphere composed mainly of carbon dioxide. This atmosphere creates a strong greenhouse effect, trapping heat from the Sun and preventing it from escaping back into space. As a result, Venus has an average surface temperature of about 900 degrees Fahrenheit (475 degrees Celsius), making it hotter than Mercury, which is closer to the Sun.
You might expect a planet to be hotter if it's nearer the Sun. This is true apart from Venus, which is the exception. Venus has a higher average surface temperature than Mercury. We believe this is because of the "greenhouse effect" of the atmosphere of Venus.
Mercury, the known planet that orbits closest to the sun, has no atmosphere.
Mercury.
Venus.
Venus
The gasses surrounding a planet is called an atmosphere and what gasses surround a planet depends on the planet. Earth's atmosphere is a combination of oxygen, nitrogen, argon and carbon dioxide and Saturn's atmosphere is comprised of hydrogen and helium.
Earth is an inner planet because it has an atmosphere. Earth Rocks!
murcury
Mars