Few people doubt global warming. Most accept that in last hundred years global temperatures have risen in the range of .4 to .8 C. Few people assume that most or all of this rise in global temperature is due to CO2 emisssion. It's unlikely that as much as a half of this increase is due to global increase CO2.
But we can reduce CO2 emission and we could do at basically zero cost. Nuclear power generation at the moment as already resulted in a huge reduction in CO2 emission. If your goal was to remove the amount CO2 emitted by all transportation [all cars, trucks, airplanes, ships] produced in the world, you could do this quite easily. Transportation simply does not add a significant amount to global CO2 emission- it's something like 20% for US total emission. If we increased the amount Nuclear power plants by 50%- the total number of nuclear plants could easily outset the amount from transportation. If American law wasn't interfering in doing this, we could have do this- Europe has been doing this- and the difference is our laws causing nuclear plants to be more costly. One could easily make the case that the environment movement has caused most of CO2 emission- by their hysteria over nuclear energy. Trying to remove CO2 by any other means is just silly and very very costly.