If CO2 is an effect (which lags) temperature changes, and it was not merely an initial event, then cause-effect relationship doesn't change.Buckwheat wrote:No, the initial cause changed.
I bolded what I believe is important in your quote .Buckwheat wrote: In the past, warming intiated by changes in Earth's orbiatal characteristics triggered a chain of events. This time, human activity (extracting hydrocarbons from deep within the earth and releasing CO2 into the atmosphere) is triggering a chain of events.
Even before humans, the Earth was naturally releasing CO2. In your own quote you use words such as "extracting" and "releasing" implying that we do not produce but release and emit already existing natural stores.
Buckwheat wrote: The definition of "feedback" is that CO2 is both a cause and an effect of global warming
This finding, in the words of Caillon et al., "confirms that CO2 is not the forcing that initially drives the climatic system during a deglaciation." Nevertheless, they and many others continue to hold to the view that the subsequent increase in atmospheric CO2 -- which is believed to be due to warming-induced CO2 outgassing from the world's oceans -- serves to amplify the warming that is caused by whatever prompts the temperature to rise in the first place. This belief, however, is founded on unproven assumptions about the strength of CO2-induced warming and is applied without any regard for biologically-induced negative climate feedbacks that may occur in response to atmospheric CO2 enrichment. Also, there is no way to objectively determine the strength of the proposed amplification from the ice core data.
Caillon, N., Severinghaus, J.P., Jouzel, J., Barnola, J.-M., Kang, J. and Lipenkov, V.Y. 2003. Timing of atmospheric CO2 and Antarctic temperature changes across Termination III. Science 299: 1728-1731.