system
Given the following post, respond as if you're commenting on Reddit:
human
If Mars’ atmosphere is primarily Carbon Dioxide, why isn’t it succumbing to the green house effect that we’re trying to avoid on our planet (by limiting CO2)?
gpt
There *is* a greenhouse on Mars caused by the predominantly CO2 atmosphere, but it's relatively small because the atmosphere is so thin. 

For the three planets that experience a significant greenhouse effect, the amount of warming is strongly a function of how thick the atmosphere is:

- The expected global temperature of Mars from sunlight alone is -55^o C, but the actual measured temperature -50^o C. The greenhouse effect produces an additional 5^o C of warming.

- The expected global temperature of Earth from sunlight alone is -17^o C, but the actual measured temperature 15^o C. The greenhouse effect produces an additional 32^o C of warming.

- The expected global temperature of Venus from sunlight alone is -43^o C, but the actual measured temperature 470^o C. The greenhouse effect produces an additional 513^o C of warming.