This is a reply to 
For the most part, you are preaching to the choir. In my case, I only pay attention to something when someone lies to me. You have probably seen the Vostok Ice Core Data graphed previously.
This is a particularly misleading example. Due to its layout, it looks like temperature follows CO2 and the last 50 years use atmospheric concentrations and not Vostok reading.
If you look at this graph where the lines overlap, we see rises in temperature coincide with CO2, but higher levels of CO2 do not maintain temperature (for example Eemian period).
I was suspicious of the atmospheric readings used in the last 50 years. Instead of continuing to base it on readings at Vostok, they have shifted to readings at Mauna Loa. I was willing to let that slide but as I did a little more research I came across the paper from which this illustration comes.
Each area takes different times to "seal". The Law Dome is closer to the coast than Vostok so it seals in about 40 years. For years, current levels mix with 30-year-old levels of CO2 (mixing zone). For 10 years, heavier gases like CH4 displace CO2 (sealing zone). The core readings are performed on the sealed ice. At best CO2 levels are an educated guess.
Source
Thirty years ago CO2 levels "were" 354 ppm and today's level is almost 414 ppm. Anyone looking at a sample from this site in 100 years would say the CO2 level today was less than 384 ppm.
This is not the least damning. I have seen papers that describe the cores taken from Vostok to be 150 years to 300 years to seal (one paper mentioned an 800 year seal period but they were vague if they were talking about Vostok).
At 150 years the hypothetical ice core would place today's CO2 level at less than 350 ppm.
At 300 years the hypothetical ice core would place today's CO2 level at less than 345 ppm.
I am not even arguing the point that CO2 is 414 today. My point is how do we know the actual CO2 levels in a previous warm period. Evidence points that the Roman Warm Period being 2 degrees warmer than now.
Roman Warm Period Sea Temperature
I am making the following a 10 percent beneficiary of this post
