I think that enough anthropogenic CO2 production could have an effect. That's just common sense. Though, I'm far from convinced that we know exactly how much of an effect it has in the broad and complex scope. It seems the reasoning is circular since we are still discovering important aspects of climate, and opposing theories have as much or more valid evidence and reasonings. All I know is that we certainly are not sure enough about it to start creating authoritarian laws and monopolized carbon markets which regular people like you and I will necessarily end up paying out for, to the benefit of those in control of it.