Hawk said
'scientifically collected data that indicates that periodic rises in natural CO2 levels are driven BY global warming'

which is what Sawzaw also pointed out with one of the graphs indicating that during the ice ages temperature changes happened before CO2 changes.

I think the key word is 'natural'. In the 'natural' environment there are various factors causing climate changes and CO2 changes may be a result of those changes. But we also know that that we are causing an 'unnatural' situation by changing the amount of CO2 in the atmosphere in a short time. Then the question is whether that unnatural increase in CO2 is likely to change the climate. We have known for about 100 years that
CO2 absorbs infra-red energy coming up from the earth and that it absorbs at a slightly different frequency to that of water.

We can now both calculate, and directly measure, the amount of radiation coming back down to earth that otherwise would have escaped into space. Its a significant number. How it translates to warming of the atmosphere is a complex matter but the essential physics is straightforward - if you put more CO2 into the atmosphere it will absorb more heat.
There is a good discussion here:
Physics Forums

If you want a paleoclimatic example of where greenhouse gases do seem to have caused massive global climate changes have a look at the references on this page
Paleocene-Eocene Thermal Maximum

Meanwhile its freezing here in Scotland!
KP