Re:A razorsharp balance (Score 1)

Sorry, but that doesn't work. Liquid CO2 can't exist with an Earth-like atmospheric pressure. Considering that the atmosphere is a little less than 80% non-O2 constituents, it's probably had a pressure of at least 0.8 atm since the Hadean era (when the Earth was born, in the infancy of the solar system). No one knows for sure how life began, but one promising theory by Stuart Kauffman proposes that autocatalytic chains of RNA can form a self-perpetuating system that could eventually evolve into the prokaryotes (bacteria) we see today. I've never heard of a theory involving liquid CO2; it isn't physically likely or biologically necessary.