moondoong your post does show a basic misunderstanding of the way c02 works in the atmosphere. Whilst co2 may be rising exponentially its effect is logarithmic in the amount of warming that will cause, ie a doubling of co2 will cause one degree of warming ie 300 ppm to 600 ppm will cause the same amount of warming as 600 to 1200 ppm will cause, so in effect temperature rise will never be exponential but will quickly taper off as the atmosphere becomes saturated with co2, what is unknown is the feedback that this will cause and to what degree this will cause increased warming this is what computer models are totally useless at calculating.
