the properties of CO2 aren't being debated by the scientific community. 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.
To deny this is the same as believing the earth is 6000 years old.
What's debatable is the amount of global warming caused by man made greenhouse gas emmisions vs. some other cause like hightened solar output.
For example -- it was so warm in the 900s, that grapes were being grown in England at it was warm enough for the Vikings to settle Greenland. All without man made CO2 emmisions.
Things cooled off back to normal around 1100. If you look at the chart in this link you'll notice that last 50 years are quite interesting ....