But, in spite of a broad consensus, the effect of that CO2 in terms of likely temperature rise is the subject of some questioning. (climate-resistance.org)
If the goal of the image had been «to portray the most likely temperature history up to the present» there would have been a single curve, not three! (realclimate.org)
So the image was supposed to portray not only the most likely temperature history, it was also supposed to portray the consistency and reliability of that history. (realclimate.org)