Guest disalarmism by David Middleton
Do you ever watch the DIY Network? The TV network where they have all the “Do It Yourself” home improvement shows? I don’t watch it because I can’t do anything like that myself. If a home improvement or repair project is much beyond duct tape and bungee cords, I’m on the phone to a professional in a heartbeat. When I was a bachelor, the pipe under my kitchen sink was leaking. So I wrapped in in duct tape and put a bowl under it. Whenever it started to leak again, I wrapped it with more duct tape. I actually left the roll of duct tape attached to the pipe, so I could easily wrap more duct tape. When I got married and we renovated the house, the plumbers actually took pictures of my “handiwork.” Is it duct tape or duck tape? But I digress…
I may not be able to fix things around the house, but it occurred to me that if the climate (e.g. average surface temperature of the Earth) is sensitive to atmospheric CO2, there ought to be a simple DIY way to demonstrate it. So, I broke out two of my favorite data sets: Moberg et al., 2005 (a non-hockey stick 2,000 year northern hemisphere climate reconstruction) and MacFarling-Meure et al., 2006 (a fairly high resolution CO2 record from the Law Dome, Antarctica ice cores).
For the sake of this exercise, I am going to assume that the “greenhouse” warming effect of CO2 is logarithmic. While this is not necessarily a safe assumption, it’s a good bet that it is a diminishing returns function… So a logarithmic function is probably good enough for a DIY project.
The first thing I did was to crossplot the Moberg temperature anomalies against the MacFarling-Meure CO2 values…
R² = 0.0741… not exactly a robust correlation. Why is the correlation so bad below 285 ppm? Well, that’s the data from the lower resolution DSS core. What happens if we only use the data from the very high resolution DE08 core?
R² = 0.1994… Roughly a 20% explained variance… Not too shabby for noisy climate data. We also get a climate sensitivity that is in line with other recent observation-derived TCR (transient climate response) estimates: 1.23 °C per doubling of atmospheric CO2 . Note that this puts the “we’re all going to die” 2.0 °C limit out to about 720 ppm CO2 and the “women, children and poor people will die” 1.5 °C limit out to about 560 ppm CO2. So, it’s not worse than we thought, unless you’re an alarmist. Then it’s probably worse than you will believe. 1.23 °C is very close to the IPCC TAR estimate of 1.2 °C sans feedback mechanisms.
If the amount of carbon dioxide were doubled instantaneously, with everything else remaining the same, the outgoing infrared radiation would be reduced by about 4 Wm-2. In other words, the radiative forcing corresponding to a doubling of the CO2 concentration would be 4 Wm-2. To counteract this imbalance, the temperature of the surface-troposphere system would have to increase by 1.2°C (with an accuracy of ±10%), in the absence of other changes. In reality, due to feedbacks, the response of the climate system is much more complex. It is believed that the overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C. A significant part of this uncertainty range arises from our limited knowledge of clouds and their interactions with radiation. To appreciate the magnitude of this temperature increase, it should be compared with the global mean temperature difference of perhaps 5 or 6°C from the middle of the last Ice Age to the present interglacial.
Things aren’t looking too good for feedback amplification.
The next thing I DIY’ed was to calculate a “CO2 temperature” using this equation:
T = 1.7714ln(CO2) – 10.305
The gray curve is the Moberg temperature reconstruction, the red dashed curve is Moberg at a constant 277 ppmv CO2. Not much difference between the gray and red dashed curves.
Let’s now apply this to the HadCRUT4 northern hemisphere temperature series (via Wood for Trees).
Northern hemisphere warming since 1979
- Total: 0.91 °C (0.01 to 0.92)
- CO2-driven: 0.33 °C (0.00 to 0.33)
- Not CO2-driven: 0.58 °C (0.01 to 0.59)
This would suggest that anthropogenic CO2 emissions are only responsible for 36% of the warming since 1979.
Let’s now look at some RCP (representative concentration pathways) scenarios.
With a 1.23 °C climate sensitivity, not even the Bad SyFy RCP8.5 exceeds the “we’re all going to die” 2.0 °C limit and RCP4.5 and 6.0 pretty well stay below the “women, children and poor people will die” 1.5 °C limit. Note than an exponential extrapolation of MLO CO2 basically tracks RCP4.5. Also note that HadCRUT4 clearly exhibits a ~60-yr cyclical variation and continued warming from the Little Ice Age (part of a ~1,000-yr cyclical variation). For those math purists who object to my geological use of the word “cyclical,” pretend that I wrote “quasi-periodic fluctuation.”
The Phanerozoic Eon
This is all well and good for the Late Holocene; but what about the rest of the Phanerozoic Eon? Thanks to Bill Illis, I have this great set of paleoclimate spreadsheets. One of the paleo temperature data sets was the pH-corrected version of Veizer’s Phanerozoic reconstruction from Royer et al., 2004. The Royer temperature series was smoothed (spline fit?) to a 10 million year sample interval matching Berner’s GeoCarb III, thus facilitating crossplotting.
Shocking!!! It yields a climate sensitivity of 1.28 °C. Royer’s pH corrections were derived from CO2; so it shouldn’t be too much of a surprise that the correlation was so good (R² = 0.6701)… But the low climate sensitivity is truly “mind blowing”… /Sarc.
References
Berner, R.A. and Z. Kothavala, 2001. GEOCARB III: A Revised Model of Atmospheric CO2 over Phanerozoic Time, American Journal of Science, v.301, pp.182-204, February 2001.
Hadley Centre. Data from Hadley Centre. http://www.metoffice.gov.uk/hadobs/hadcrut4/data/download.html Data processed by www.woodfortrees.org
Illis, B. 2009. Searching the PaleoClimate Record for Estimated Correlations: Temperature, CO2 and Sea Level. Watts Up With That?
MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, T. van Ommen, A. Smith, and J. Elkins (2006), Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP, Geophys. Res. Lett., 33, L14810, doi:10.1029/2006GL026152.
Moberg, A., D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. Karlén. 2005.
Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data. Nature, Vol. 433, No. 7026, pp. 613-617, 10 February 2005.
NOAA. Data from NOAA Earth System Research Laboratory. http://www.esrl.noaa.gov/gmd/ccgg/trends/ Data processed by www.woodfortrees.org
Royer, D. L., R. A. Berner, I. P. Montanez, N. J. Tabor and D. J. Beerling. CO2 as a primary driver of Phanerozoic climate. GSA Today, Vol. 14, No. 3. (2004), pp. 4-10
Featured image from Wikipedia.
The DIY Climate Sensitivity Toolkit
DIY Climate Sensitivity Toolkit
Gaffer tape FTW.
I’ve got a climate sensitivity toolkit, it’s called the laws of physics: and they say CO2 has zero impact on climate, because when the calculations are done correctly, so the answers match the International Standard Atmosphere, CO2 isn’t even mentioned; much less calculated as influencing temperature.
“I may not be able to fix things around the house, but it occurred to me that if the climate (e.g. average surface temperature of the Earth) is sensitive to atmospheric CO2, there ought to be a simple DIY way to demonstrate it. So, I broke out two of my favorite data sets: Moberg et al., 2005 (a non-hockey stick 2,000 year northern hemisphere climate reconstruction) and MacFarling-Meure et al., 2006 (a fairly high resolution CO2 record from the Law Dome, Antarctica ice cores).”
1. Wrong from the start. You should not start with your favorite datasets. And if you DO, you had better
check all the other datasets. WHY? because you want to question your own beliefs. In this
case, your belief that these datasets are somehow special. It will also let you estimate your structural
uncertainty.
2. You wont get sensitivity by looking at only c02.
A little refresher in basic AGW theory.
1. The temperature of the planet ( any planet ) is a function of the External forcing.
That’s the sun.
2. This temperature can be increased by the presence of
GHGS.. that’s water, c02 , methane, black carbon, etc. secondary effects
3. This temperature can also be increased (or desceased) by changes in albedo, land use,
and aerosols.
So, you need to have ALL THE FORCINGS.
You can find them all online. CMIP experiments have files for the all the forcings we know.
It does not have forcing for things we can only speculate about. ya, needs to has numbers.
Once you have all the forcings, you can estimate the climate sensitivity. ya need to do this first.
That is a factor that allows you to calculate change in temperature from ALL the changes in Watts.
Once you have that, then you can estimate TCR and ECS.
If I was going to do all of that, it wouldn’t be a simple DIY climate sensitivity toolkit.
More fake pseudo-science from Mosher, the man who was mocked to his face by the person releasing the Climategate emails, saying to the moronic Mosher ”Still believe it’s real?”
There are no ”beliefs” in actual hard sciences regarding temperatures of gases. The International Standard Atmosphere’s fundamental matter-energy relationships are calculated, and that’s how it’s done. Only a non scientific looper thinks his “beliefs” matter in calculating the temperature of the Atmosphere.
What utter nonsense! Try taking data over the last 10,000 years! You get a NEGATIVE sensitivity to CO2.
Setting aside the fact there are no suitable 10ky data sets for this sort of exercise, Holocene CO2 wasn’t fluctuating very much on Antarctic ice core records and almost all of the fluctuations were driven by temperature changes. The only period over the past 10ky when CO2 might have been a temperature driver.