When you say someone is in denial, you are compounding a simple logical discussion on one focused topic with an attack on your overall belief system. When this narrow belief system is shared by others and deviant thought even by believers is attacked (the recent example of Michael Moore is an obvious example. When people act this way they are a religion in the sense they have core beliefs and anyone who does not espouse all of these beliefs is attacked. But you went on to at least attempt a discussion on the data to defend your belief system so that's a start.
The empirical experiment of significantly reducing our industrial output and therefore our CO2, will shed important real life measurable results and will change our understanding of role of natural vs man-made inputs. It may turn out that man-made inputs are even more important or that they are not. Prediction for a reduction at the end of the year are fine but not empirical data and you have faith in them and I will wait for the data.
Interested parties and scientists should keep an open mind. The nice thing about this situation is that we will have a short term answer vs waiting decades or centuries.