I can say one thing for sure. I'd prefer a global temperature increase than another ice age.
We could adapt to increased temp much easier than a lowered temp. Besides, increased CO2 and warmer climate makes for better plant-life growing conditions. Look at China, the air quality is bad but daaaamn those trees are green and healthy.
In my opinion, we still know far too little about the larger cycle of our planets temperature. We know there was a massive ice age where the global temperature dropped. But we don't know for sure why. We also can't tell what the temperature was before then, it's all just guess work. This planet has been around for far longer than we have been able to measure the temperature and our records are miniscule when compared to the age of this world.
Also, the major flaw I see in the arguments for man made warming is that it assumes the natural production and absorption of CO2 is relatively 'fixed' which is crazy. higher concentration of CO2 and warmer climate means rapid plant growth which in turn increases CO2 absorbed by plants while also providing an increase of food for herbivores which in turn increases food for carnivores and so on. This planet has a pretty awesome self balancing system, it is not as fragile as people make it out to be.
Also, it is in a constant state of change. To expect this world to stay in a fixed climate and state is stupid, I instead think we should be more focused on developing our technology for adaptability rather than taxing people into the ground to try and control the weather.
You fix problems with innovation, not with taxing people.