NTZ reader and contributor Ed Caryl brings us his newest essay. This one is about the climate’s (low) sensitivity to CO2.
On CO2, Did You Know That… ?
By Ed Caryl
Nearly all the papers on CO2 and high global warming are based on climate models, not actual data.
- Did you know that there is one paper that uses satellite data to actually measure CO2’s affect on climate?
- Did you know that the temperature figure for CO2 doubling (climate sensitivity) found in that paper is 0.6°C?
Dr. Roy W. Spencer and Dr. John Christy are the “fathers” of satellite based global temperature measurements. Dr. Spencer is also the author of the book, The Great Global Warming Blunder. Dr. Spencer and Dr. William D. Braswell co-authored the above paper.
First, to prepare you, some mathematics:
The formula for the amount of warming due to a doubling of CO2 is:
X = ∆T * (3.7 W/m2)/∆F
Where X is the warming in °C,
∆T is the equilibrium temperature change measured in °C,
∆F is the sustained forcing in W/m2, that produced that change,
The 3.7 W/m2 figure is the radiative forcing due to doubled CO2 as measured at the top of the atmosphere. This figure is from the IPCC 2001 report, and is agreed on by most researchers, including Spencer in The Great Global Warming Blunder (page 48).
Any sustained forcing of less than 3.7 W/m2 is positive feedback, resulting in an X of 1°C or more. Any sustained forcing more than that figure is negative feedback, resulting in an X of less than 1°C. If there is no feedback, positive or negative, the figure for CO2 doubling is 1°C. The IPCC figures, 1.5 to 4.5°C, assume positive feedback, mostly from water vapor.
Most of the climate sensitivity calculations use climate models, rather than real-world data. All produce climate sensitivity numbers of more than 1°C, most centered around 3°C. Roy Spencer used actual satellite temperature measurement data to find the real-world climate sensitivity. In another paper, found here, he describes evidence that the forcing is between 6 and 8 W/m2, thus climate sensitivities for CO2 doubling of from 0.46 to 0.6°C, or 0.8 to 1°F. This low number is attributed to negative feedback from clouds. This is an inconsequential amount of warming, and even that may not be reached if CO2 does not double.
This low climate sensitivity along with ocean cycles like the AMO, ENSO, and PDO may be the reason for no warming since 1998. See Bob Tisdale’s post in WUWT here for reinforcement of that idea.
Have those figures been published in a peer-reviewed journal? Yes, in the Journal of Geophysical Research. See: Spencer-Braswell-JGR-2010.pdf
Is there any independent confirmation of such low climate sensitivity? Stephen E. Schwartz (2007) (also peer reviewed in the JGR) has studied the ocean heat capacity, and has produced two significant numbers: 1) the time constant for temperature changes is 5 ± 1 year, not the much longer periods touted by others. And 2) the climate sensitivity measured this way is 1.1 ±0.5°C, very close to the no feedback case, but not excluding Spencer and Braswell’s numbers. Schwartz uses GISS temperature data, not the somewhat lower satellite data, so his climate sensitivity number may be high.
No amount of expeimentation can ever prove me right; a single experiment can prove me wrong.
Well, here are two. (Three, if you count Bob Tisdale’s post.) These are “experiments” that use actual real-world data, not models. The science is settled? You be the judge.