By Andy May
Nicola Scafetta has written a new paper (Scafetta, 2021) in Atmosphere on a new millennial surface temperature reconstruction. This is his latest “what if the models are accurate?” analysis. Scafetta’s idea is, let’s assume a model is correct, what are the implications?
Previously, he examined the PMOD solar model, by assuming it was correct and the Sun is invariant long-term, does this make sense? Another example, if we smooth through the urban heat island effect (UHI), do we eliminate it, or just smear it out, so the data looks better, but is just as inaccurate? In the latter post, on UHI, I wrote:
“Relative to 1940 to 1960, the original HadCRUT curve shows 0.59°C of warming and 0.48°C using Scafetta’s corrections. The UAH record shows 0.44°C. The CMIP5 climate models show 0.78°C of warming.
It is possible, according to Scafetta’s correction, that non-climatic biases may have contributed a fifth of the reported HadCRUT global warming since 1940-1960. It is also possible that the CMIP5 climate models may overestimate warming by a third. These are significant problems.”
Computer models have a downside. They can be used by those on the other side of the debate. If they lead to absurd or inconsistent conclusions, they make you look foolish. What if Scafetta assumed that the HadCRUT recent temperature record is correct? Then he further assumes that the CMIP5 (Coupled Model Intercomparison Project Phase 5) ensemble mean is correct, what does this mean for past temperatures? Do we find inconsistencies?Continue reading