Here is a recent Discussion Paper by Statistics Norway casting doubt on the accuracy of global climate models! It seems to be very recommendable!
It confirms that these climate models are not able to correctly backcast nor forecast temperature data. Global Warming is a hoax and Climate Change is a religion!
This paper also discusses periodic changes in solar activity as a possible cause for climate change on earth. Very plausible! We still know shockingly little about the sun.
Caveat: I did not have the time to read this 123 pages long paper.
Here are a few excerpts:
- "In the global climate models (GCMs) most of the warming that has taken place since 1950 is attributed to human activity. Historically, however, there have been large climatic variations. Temperature reconstructions indicate that there is a ‘warming’ trend that seems to have been going on for as long as approximately 400 years. Prior to the last 250 years or so, such a trend could only be due to natural causes. " (p. 5)
- "Recently, Zharkova (2020) and Zharkova et al. (2015) have studied the role of the solar background magnetic field in defining solar activity. By applying principal component analysis, they were able to quantify the observed magnitudes of magnetic field at different times and consequently make long-term prediction of solar activity on a millennium timescale. Their approach revealed a presence of not only 11-year solar cycles but also of grand solar cycles with duration of 350–400 years." (p. 12)
- "According to the research by these authors there will be an upcoming grand solar minimum, when solar magnetic field and its magnetic activity will be reduced by 70 per cent. During this grand minimum, one would expect a reduction of the average terrestrial temperature, ceteris paribus, by up to 1.0°C in the decade 2031–2043." (p. 12)
- "... At the outset, it is not entirely clear what it means to track global temperatures over time since global temperatures are not observed, they are constructs. Unfortunately, there is, as mentioned above, no obvious way of how global temperatures should be constructed, as it is not clear how the temperature output from GCMs should be interpreted." (p. 16)
- "A weakness of the tests reviewed above is that the time series of measurement errors in the global temperature constructs most likely are non-stationary with unknown properties." (p. 18)
From the abstract:
"Subsequently, we review key properties of global climate models and statistical analyses conducted by others on the ability of the global climate models to track historical temperatures. These tests show that standard climate models are rejected by time series data on global temperatures. Finally, we update and extend previous statistical analysis of temperature data (Dagsvik et al., 2020). Using theoretical arguments and statistical tests we find, as in Dagsvik et al. (2020), that the effect of man-made CO2 emissions does not appear to be strong enough to cause systematic changes in the temperature fluctuations during the last 200 years."
