FreeWilly
Q Earth has been much hotter before (holocene, Medievil periods) What do you think was the cause of this?
Previous highs and lows in average global temperatures have happened for a variety of natural reasons; solar variation, several orbital/rotational cycles, etc.
Never before have billions of tons of stored CO2 been released into the atmosphere in such a short space of time. At the same time we see an unprecidentedly rapid change in temperatures. All the various natural factors do not explain this. We should be somewhere else on the graph according to previously observed natural variations, given the solar and orbital etc. inputs.
Now, it might just be a big-ass coincidense, and there is some natural cycle we don't know about. Or it might be using fossil fuels like they're running out... oh, yeah...
Q How would you explain the "lag effect" of CO2 exiting previous Ice ages - namely, temperature rise preceding CO2 concentration increases in nearly all glacial terminations?
http://www.realclimate.org/index.php?p=13
Q If humans were never on the Earth, what would you expect Earths climate, specifically in regards to temperature, to be doing? Does it makes sense that the ~18,000 year warming trend that is exiting us from the last ice age would continue, stall or reverse?
That is almost begging the question with a reply that isn't relevent... the general trend does not explain the current rapid rise, nor is the level of CO2 consistent with what it would 'normally' be at this point in a general trend. What the climate WOULD be isn't the question, why it is as it is, is. I love that last bit, "it is as it is, is". LOL
Q What role does CO2 play as a Greenhous Gas? Specifically, of all the known greenhouse gasses in our atmosphere, what portion or percentage does CO2 occupy? How does Co2 compare to say... water vapor?
Again, begging a question that the reply of which does mean anything in this context. So what if water vapour is the main greenhouse 'gas'. We are not talking about an increase in water vapour, we are talking about an increase of CO2 coinciding with a period where some other factor (like an increase in water vapour) can not explain the temperature rise. Funny point though; an increase in temperature also leads to an increase in water vapour...
Would you believe someone who told you the smell in the room had nothing to do with them farting? And saying the room would get smelly anyway at this time of day? When the room had never smelled that bad at that time of day before the farting?