There is actually another planet in the solar system that is affected by a runaway greenhouse effect. I'm talking about Venus where the greenhouse effect there is too large that temperature on the sourface is around 854 degrees Fahrenheit and has a 96% CO2 in it's atmosphere, and all the water there is boiled. Scientist theorize that Venus was a planet much like earth and for some reason entered this greenhouse effect.
Thanks for posting and making people aware of these things so we can prevent catastrophes.