In its last Summary for Policymakers, on page 14 [1], the Intergovernmental Panel on Climate change (IPCC) writes : “Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence), extremely unlikely less than 1°C (high confidence), and very unlikely greater than 6°C (medium confidence).”
In its jargon the term equilibrium climate sensitivity (ECS) means the average temperature rise at the surface of the globe that the climate system would show for any doubling of the atmospheric concentration of carbon dioxide (CO2).
Since the beginning of the industrial era the CO2 concentration rose from 280 to 400 ppm, a 43% increase.
What would then be the calculated temperature if we use the IPCC values?
It needs to be remembered that the radiative forcing implied in the warming by so-called greenhouse gases varies in proportion to the logarithm of the concentration. Thus a 43% concentration increase will result in approximately half of the ECS (51.5%).
Calculated temperature increases implied by IPCC’s statement:
| IPCC parameter | ECS °C | Calculated ΔT °C |
|---|---|---|
| Low | 1.5 | 0.77 |
| Medium (table 9.5 of the full report) |
3.22 | 1.66 |
| High | 4.5 | 2.32 |
| Actually observed total temperature increase | approx. 1.0 °C |
Thus we can interpret that, in its lowest estimate, IPCC attributes 77% of the observed warming to CO2, leaving the rest to other anthropogenic sources such as methane and other emissions of so-called greenhouse gases, and soot. Almost nothing is left to natural causes, because none was sought and therefore none was identified.
Worse, in its medium scenario CO2 would have contributed to 166% of the observed warming which would imply that other causes would have contributed to a 0.62 °C cooling, still without discussion and quantification.
The same observation applies for the high ECS estimate where a cooling of not less than 1.32 °C should have taken place if we would not have burnt fossil fuels and produced cement. We would find ourselves in a regime even colder than the minimum of the little ice age, from which we began to get out well before any human consequence of the industrial era could have played any warming role. IPCC does not tell this to decision makers, why?
Reader: use your own mind to assess if the above IPCC statement has anything to do with reality.
Other approach.
Radiatice forcing is linked to the ability of certain gases to absorb electromagnetic radiations in the infrared range, such as water vapour, CO2, methane, nitrogen oxide etc. There is one and one only seminal work by Myhre et al [2] that calculates the primary forcing resulting from concentration changes of some of these gases. It is used it many publications and considerations that are reviewed by IPCC.
For CO2 the practical formula is given as
In a revisited calculation. F.K. Rheinhart (FKR) [3] found that the Myhre parameter 5.35 should be corrected down to 1.88.
Using Myhre’s formula and a feedback calculation as described in another paper of mine (MR) [4] the resulting temperature increases would then be:
| Parameter | Implied Myhre | ECS | Primary Forcing W m-2 | ΔT calc K |
| FKR | 1.88 | 0.19 | 0.67 | 0.10 |
| MR | 5.35 | 0.53 | 1.91 | 0.27 |
| IPCC low | 15.04 | 1.50 | 5.37 | 0.77 |
| IPCC medium | 32.29 | 3.22 | 11.52 | 1.66 |
| IPCC high | 45.13 | 4.50 | 16.10 | 2.32 |
The IPCC’s assumed ECS values imply the multiplication of the Myhre parameter by 3 to 9!
And so far, aside F.K. Reinhart on the downside, nobody has refuted the validity of this formula. Note also that at the highest IPCC estimate, the primary forcing due to a 43% increase of CO2, would be 4.7% of the total incoming solar irradiation.
Reminder: the energy that the entire humanity produces and consumes represents 0.0092%of the incoming solar irradiation.
With Myhre’s formula and a mean feedback from other climate phenomena the temperature increase attributable to CO2 is a mere 27% of the total observed. This leaves room for explanation of other variations that took place before the industrial era, thus not involving this gas.
What to do with statements that are not confirmed by observations and that imply implausible physical consequences [5]?
With the clout of IPCC and the accumulated particular interests that developed since the climate has been discovered as the opportunity to indoctrinate the entire world, what is written here will just be ignored. Or, courageous reader, you will disseminate it further.
[1] IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)].Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
[2] Myhre et al.
New estimates of radiative forcing due to well mixed greenhouse gases.
Geophysical Research Letters, Vol. 25, No.14, pages 2715-2718, July 15, 1998
http://folk.uio.no/gunnarmy/paper/myhre_grl98.pdf
[3]F. K. Reinhart,
www.eike-klima-energie.eu/uploads/media/Infrared_absorption_capability_of_atmospheric_carbon_dioxide.pdf .
[4] Michel de Rougemont
Temperature Anomalies and Carbon Dioxide, a Correlation Attempt
https://hal.archives-ouvertes.fr/hal-01146608
[5] See also explanations on a gross error of one of the highest ranking priests of the climate curia:
http://climate.mr-int.ch/index.php/en/modelling-uk/feedback-uk/ipcc-mistake/
I never received any correcting statement from the implied person, thus the critique must be right.