"Without naturally occurring greenhouse gases, Earth's average temperature would be near 0°F (or -18°C) instead of the much warmer 59°F (15°C)." [From here: http://www.giss.nasa.gov/research/briefs/ma_01/ ]. "Without this greenhouse effect, the average surface temperature would be 255 degrees kelvin (-18 degrees Celsius or 0 degrees Fahrenheit); a temperature so low that all water on Earth would freeze, the oceans would turn into ice and life, as we know it, would not exist. " [From here: http://ase.tufts.edu/cosmos/view_chapter.asp?id=21& ]
Without an atmosphere then it is a fair assumption that we would be similar to the moon, although we do have water to help moderate temperature, but the post title above says "Thankfully we have greenhouse gases or we would fry", when it should say "Thankfully we have an atmosphere or we would fry (and freeze)."
We'd also all be dead without the ozone layer. The ozone layer (O3, generated by interaction with UV radiation from oxygen, produced by plant photosynthesis) is what originally allowed life to develop outside of the oceans.
There a lot of important, life sustaining attributes of the atmosphere, which is why should bloody well not mess with it!
