I've read water vapor is 95% and that our contribution via CO2 is something less than 0.2%.
Also read that we've had levels as high or higher than 380ppm prior to the industrial age.
1) This is at least partially wrong, and even if it were right, it's irrelevant with regards to this debate.
Firstly, what you are talking about is the entire thermal infrared absorption capacity of our atmosphere. If we didn't have it, no life would ever have existed on earth. Humans contribution to global greenhouse gasses is relatively small, but human society, and life in general, is extremely sensitive to even tiny climate fluctuations.
Secondly; Water has an effect that is variously estimated at anywhere from 40%-70% of total infrared absorption in the atmosphere, but such estimations are fraught with inconsistencies. It is certainly not 95%.
2) Atmospheric carbon dioxide concentration is almost certainly at it's highest level in 800,000 years, and there is good evidence that it's close to, or at, it's highest concentration in 15 - 20 million years. How far back were you wanting to go?