You keep on bringing up this graph and and I don't know what you're trying to show with it. It is clear to everyone that there must be some kind of feedback mechanism that couples temperature and CO2 concentrations so that an excursion in one generates a counter force that tends to limit it. No doubt there are many other intermediate mechanisms involved (ice cap reflectivity, %cloud cover, sequestration of CO2 in aqueous solution or marine carbonates, etc). The earth is a self-regulating system, and the long history of the biosphere proves that at least it has been able to remain hospitable to life for billions of years.

This will cause a chaotically cyclical pattern in any measured parameter, but more important, if you could zoom in on that curve to a much higher resolution, you would probably see more local temporal effects superimposed on it too. The Dow is a very similar phenomenon, you can't tell which temporal scale you're looking at without checking the grid spacing.

Your ice-core data is very low resolution (one graph square is 10K years). Each data "point" may be the average of centuries, it represents very long term phenomena and trends (probably mostly astronomical and geological). It also reflects data collected at the earth's surface, where the ice formed, not at high altitudes where greenhouse gases have such a leveraged effect on atmospheric IR opacitiy. But it does give us one important fact: Temperature and CO2 concentrations are highly correlated, even if not causal, and the concentrations are in the realm of those possible to human industrial activity.

The earth, life and probably humanity will survive any human-induced climate change, it has certainly endured much worse from purely natural phenomena. The question is whether human civilization as we know it will be able to survive a rapid excursion leading to extreme weather changes, a short term blip that won't probably even show up on your ice cores, but that could alter the world economic landscape. We simply cannot continue dumping millions of tons of greenhouse gases (not to mention particulates and other pollutants) into the atmosphere without expecting some kind of consequences, changes for which there is strong circumstantial evidence accumulating (the glacier data and many documented biogeographical shifts). We both agree on one thing: We don't know how the earth climate system works. Given that, it is irresponsible if not suicidal, to continue using it as a sewer as we have so far. We should have been taught that lesson by our oceans, our coastal waters, our lakes and streams, our own municipal sewage disposal technology. The burden of proof is on the polluters.