Italics here are to be read as if in a dream state….. sort of like the wavy line thingys on sitcoms that cue the audience that the actor is in a dream state of sort ………
One of the biggest problems with all of this climate science is the fact that we don’t have a test earth to experiment and observe, so the empirical evidence is lacking. Well, this has been a vexation for all of us. If only we had a test earth that would include all of the variables, oscillating and cyclic events, and all of the other factors that go into our climate. We could then drop in some CO2 and see how the test earth would react! Then we could have some empirical evidence to go by and draw our conclusions based on physics and observations! Well, that’s just a pipe dream we’ll never have a test earth with all of the natural variants and then add in the impact modern man has made on this earth.
But, if we did, we could set the atmospheric CO2 level back to where they believe the pre-industrial setting was…… about 280ppm ….. and then we could over time add CO2 to the atmosphere and observe the changes. Of course we’d have to include all of the things mentioned earlier, like the PDO, the AMO, the solar cycles, volcanoes…. well again….. just a pipe dream.
We have over 130 years of temperature measurements with the start point of atmospheric CO2 levels at ~280ppm. Since then atmospheric CO2 has increased by almost 120ppm. Or, 43% increase towards a doubling of CO2. GISS puts the temperature rise at about 0.7°C – 0.8°C. If GISS is accurate, and, if the posit of the relationship CO2 has with temps is correct, such as the logarithmic effect, then calculating a linear relationship would somewhat overestimate the expected heating. The 0.8°C represents 43% of the next doubling of CO2. 0.8/0.43 = 1.86 expected linear increase to represent the high end. 0.7/0.43 =1.63 to represent the lower end. Subtract the 0.8 from 1.86 for the already accomplished warmth and the 0.7 from the 1.63 for the high and low expected resultant. Again, assuming the veracity of GISS is acceptable and the CO2/temp relationship exists, completion of the next doubling of CO2 (560 ppm) we can expect less than 1 degree increase when factoring in the posited logarithmic relationship. Linearly we could expect a high/low 1.06/0.93 degree increase when atmospheric CO2 is at 560ppm. All known and unknown cyclic and intermittent occurrences are included in the calculation except for those which occur outside the 130 year parameter.
Well, I guess we’ll never know. How could we? Our models can’t factor in events and effects we are unaware of, nor do we understand the weightings of such events. We’ll just have to wait and see what is going to happen……. sigh. Well, it was fun dreaming…….