New Research: “CO2 Influence On Global Temperature Development Since1860 Only Half As Large As IPCC Estimate!

A remarkable publication on solar influence on climate goes unnoticed

By Prof. Fritz Vahrenholt (Die kalte Sonne)
(Text translated/edited by P. Gosselin)

On November 3, 2021, the renowned scientific journal Climate published a paper on solar influence on climate. The paper by the renowned solar researcher Dr. Frank Stefani from the Helmholtz Zentrum Dresden-Rossendorf is entitled: “Solar and Anthropogenic Influences on Climate: A Regression Analysis and Tentative Predictions” and concludes that the influence of CO2 on the development of global temperatures from 1860 until today was only about half as large as the last report of the Intergovernmental Panel on Climate Change (IPCC) assumed.

As a reminder, the IPCC concludes that 98% of the warming ( 1.07 degrees out of 1.09 degrees) is human-induced. According to Stefani’s analysis, the solar influence accounts for 30-70%.

Stefani examined the course of the geomagnetic aa – index, which reflects the strength of the earth’s magnetic field. This index has been measured in Cambridge and Melbourne since 1844 and reflects the influence of solar activity. In earlier publications, Stefani had already been able to prove that the 11-year solar cycle is triggered by the gravitational forces of Venus, Earth and Jupiter, which are in orbital resonance every 11.07 years (here, here and here).

Since the Sun – influenced by all the planets (especially Jupiter and Saturn) – also moves around the center of gravity of the solar system, solar cycles arise that have become known in temperature history as the 193-year Suess-de Vries cycle and the 90-year Gleissberg cycle.

Only 1°C warming by 2100

In a coupled regression analysis of the aa index, CO2 and temperature, Stefani was able to determine a CO2 climate sensitivity TCR (Transient Climate Response at a doubling of the CO2 concentration) of 1.1 +/- 0.5 °C. Because of the cyclical nature of solar activity, Stefani was able to venture a forecast of the aa – index for the next 150 years. According to this, even with a further increase in CO2 concentration of 2.5 ppm per year, there would only be a temperature increase of 1° C by the end of this century.

Stefani : “The 2°C target could probably be achieved without drastic decarbonization.”

Warming will be largely compensated for by declining solar activity

In the case of moderate decarbonization (increase to 500 ppm), the warming effect of CO2 would be largely compensated for by the declining activity of the sun, and warming would come to a standstill. Perhaps German state prime minister Michael Kretschmer, who is fighting against breaking the agreement to phase out lignite mining in 2038 (now in the coalition agreement “ideally 2030”), should ask Mr Stefani of Dresden-Rossendorf to come to the state chancellery in person.

In 2012, his predecessor Stanislaw Tillich invited Sebastian Lüning and myself to the Saxony cabinet to present the theses of the book “The Forgotten Sun” to all ministers. Those were the days!

The reconstruction with a climate sensitivity of CO2 of 1.1°C (one third less than the assumption of the Intergovernmental Panel on Climate Change) is taken from Stefani’s work in the following chart. The divergence from 2000 onwards is due to the strong temperature increase caused by the El Nino in 2016, which, however, regressed slightly after 2018.

7 responses to “New Research: “CO2 Influence On Global Temperature Development Since1860 Only Half As Large As IPCC Estimate!”

  1. New Research: “CO2 Influence on Global Temperature Development Since1860 Only Half as Large as IPCC Estimate! – Climate-

    […] New Research: “CO2 Influence On Global Temperature Development Since1860 Only Half As Large As… […]

  2. John Hultquist

    Thanks Pierre.

    Very interesting. I’m hoping there will be reviews of this work by other solar researchers. It is beyond my pay grade-skill set.
    The increase of CO2 at Mauna Loa for the past year (Nov to Nov) was 1.89 ppm. The number used in the text is 2.5 ppm and over an 80 year, to end of century time frame, this would be significant if continued. Warming, if CO2 is responsible, needs to be adjusted down.

  3. RoHa

    This is nonsense. What could the Sun possibly have to do with the climate?

  4. Ray Tomes

    You state that Suess-de Vries cycle is 193 years, but it averages 207 years over many thousands of years. It is close to a peak right now. There is also a 2300 year cycle in the Sun which is still rising.

  5. Cyan

    Based on experiments with the NASA Planetary Spectrum Generator (PSG), I have come to a very similar conclusion; Warming for a doubling of CO2 from 275ppmv to 550ppmv cannot be more than about 1K (0.93K).

    The essay is here:

    and an interactive tool that compares the PSG data and IPCC forecasts is here:

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    […] New Research: “CO2 Influence On Global Temperature Development Since1860 Only Half As Large As… […]

  7. Brett Keane

    GHE? Not possible! Gases can only expand or contract, rise or fall, according to input and Thermodynamics eg efficiency of energy use. In any free atmosphere there is no GHE. See NASA Planetary Tables
    Nor can they retransmit energy from cooler heights to warmer surfaces below, again Thermodynamics. Water Phase Changes however can handle ten times the current energy flows. Poisson (Ideal Gases);Maxwell (Kinetics and LOTD); Einstein 1917 (Quantum Theory). Old Stuff…… Brett Keane, New Zealand.

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