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.