I specifically did not do that in my post. Clearly there are a vast multitude of variables that affect global temperatures. The vast majority of these are completely beyond our control - volcanism, sunspots, etc. That is what I referred to as the "baseline", which Baron seems to be very excited about since it may mean that we will be able to grow corn in Greenland again.
If you overlay this baseline with the increase in CO2 in the recent past, caused almost entirely by humans, you will experience higher temperatures relative to said baseline effects. The degree that these temperatures will be higher is still open to debate because of feedback effects. But there is no debate about the direction of the effect.
I suppose you can continue to console yourself by looking at some temperature measurements and shouting "eureka!" when you point at the change in CO2 between them. However, you should at least recognize that you have not considered the thousands of other variables that went into those temperature changes.
I will say it again - If an observer looks at a graph of CO2 concentration in our atmosphere and doesn't feel the slightest twinge of concern, there is something wrong with that observer. This is a greenhouse gas, it will make things warmer, and we are the cause - that is beyond dispute.
Note: This is an old graph, as you point out below the current reading is actually 410ppm