And to continue on my point about the data used to show the CO2 lag, CO2 has been showed consistently to be the contributing factor behind the Greenhouse Effect. There's no way you are such a skeptic and non-believer to not believe the Greenhouse Effect does not exist. So with that, throughout history (from scientific data), CO2 ppm in the atmosphere never exceeded 300 ppm. NEVER. There were natural changes in the climate and the natural world flowed with itself, different events causing different warming and cooling trends. However, since man and industrialization came along we have not only exceeded 300ppm, we skyrocketed CO2 concentration to above 400ppm in a timeframe unprecedented by any increase in history. This contributes directly to the Greenhouse Effect, but maybe you dispute that too, I'm not sure how crazy you really are. In case you need a refresher on the effect, here's a quick and easy Wiki:

https://en.wikipedia.org/wiki/Greenhouse_effect