A new critical look at climate models
A blockbuster report by Norway’s Statistical Institute says 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.
Basically the paper rejects the driving theory of the current global warming hysteria. The document also says “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.” The two researchers note that most climate models assert that most of the warming that has taken place since 1950 is attributed to human activity.
The paper, made public in September, is titled “To what extent are temperature levels changing due to greenhouse gas emissions?” The authors are identified as John K. Dagsvik of the Oslo-based institute and Sigmund H. Moen, a retired civil engineer.
The document is labeled a discussion paper and reports no new observations. Instead, the authors analyze with statistics the ability of current climate models to duplicate the actual historical temperatures. The paper is available in English here:https://www.ssb.no/en/natur-og-miljo/forurensning-og-klima/artikler/to-what-extent-are-temperature-levels-changing-due-to-greenhouse-gas-emissions/_/attachment/inline/5a3f4a9b-3bc3-4988-9579-9fea82944264:f63064594b9225f9d7dc458b0b70a646baec3339/DP1007.pdf
The key point, says the document, is that “. . . standard climate models are rejected by time series data on global temperatures.” The authors cite “reconstructed temperatures over the past 420,000 years obtained at the Vostok station, Antarctica.” The record spans over four glacial periods and five interglacial periods, including the present, they said.
In explaining the origin of Antarctic ice core data, the authors said “The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core. The proportions of different oxygen and hydrogen isotopes provide information about ancient temperatures, and the air trapped in tiny bubbles can be analyzed to determine the level of atmospheric gases such as CO2. Since 1979 satellite observations in the troposphere have been used to estimate temperature.”
Other researchers have used other methods, such as tree ring studies and ice cores form Greenland, to estimate the historical temperatures, they note, adding:
“These data indicate that warmer temperatures were the norm in the earlier part of the past 4,000 years, including century-long intervals nearly 1°C warmer than the decade (2001–2010).”
The authors said they used 75 temperature time series from 32 countries, including the United States, in the statistical analysis in the paper.
The authors also discuss possible natural reasons for climate variability, such as the earth’s rotational cycles. Proponents of man-made global warming typically attribute warming to human’s release of carbon dioxide and methane into the atmosphere.
Global climate models has only been subjected to rigorous empirical testing by means of advanced statistical methods since 2016, they said.
Another major conclusion of the authors is that their regression analysis indicates that with the current level of knowledge, it seems impossible to determine how much of the temperature increase is due to emissions of CO2.
