They all agree that CO2 is a greenhouse gas that traps in heat. They all agree that our CO2 output is higher than its ever been. Therefore they all agree that our CO2 output contributes to global warming.
No they don't. Many believe the idea is silly. Wikipedia entries (you referenced one) are not scientific, quite susceptible to propaganda and manipulation which has been shown on many occasions. Google the oppositions position and you will find many that believe there is no connect.
In fact, there are many who believe that we are actually at a very low point in the natural cycle of CO2 levels. Additionally it is widely believed that more CO2 correlates with a more robust biosphere (plant life has thrived during times of high level CO2; horticulturalists are aware if this as many greenhouses are enhanced by addition of equipment to produce CO2--point here being that if anything more CO2 is a good thing).
As far as ice ages etc, those are much more robustly supported by theories involving solar cycles.
Those who oppose climate change are often threatened rather than refuted--to me, that further indicates they are desperate. Additionally they have effectively been caught rigging the study for decades--if you have no agenda then what's up with the systemic errors (read: errors support their foregone conclusions, not random). This raises valid suspicion.
The real purpose of CO2 theories is to provide an excuse for carbon taxes that literally make you guilty for breathing and require you pay tribute to the system.