Cook et. al. are frequently quoted when non-scientists state that „97%“ percent of „climate scientists“ support anthropologically caused global warming (AGW) theory. We have revised raw data underdlying Cook’s study to get out the figure more exactly and to find out about potential methodological errors.
Raw data of Cook et. al. study is available on the internet:
Over 10.000 single scientific studies have been researched by Cook et. al. wether they support AGW theory, have an indifferent position or do not. 7 categories therefore have been implemented by the authors:
- 1, Explicitly endorses and quantifies AGW as 50+%
- 2, Explicitly endorses but does not quantify or minimise
- 3, Implicitly endorses AGW without minimising it
- 4, No Position
- 5, Implicitly minimizes/rejects AGW
- 6, Explicitly minimizes/rejects AGW but does not quantify
- 7, Explicitly minimizes/rejects AGW as less than 50%
(Source: Cook et. al. Raw data)
Category 1 to 3 can be seen as affirmative concerning AGW, 4 is neutral and does not give any statement, 5 to 7 deny AGW theory to a more or less extent.
Each study examined has been groupud into one catagory by Cook et. al. Categorization is found in the raw data sets by the end of each line referring to one single study. An integer number int the range of 0 < n < 8 marks the respective category an examined study has been grouped into.
To get the statistical distribution of these numbers we have written a very compact snippet of software reading the information directly from the ASCII-file and increasing a single variable counter each time a study fell into one of the 7 catagories.
The following categories were formed by Cook et. al., we obtained the respective numbers by software filtering:
|1,Explicitly endorses and quantifies AGW as 50+% :||58|
|2,Explicitly endorses but does not quantify or minimise||850|
|3,Implicitly endorses AGW without minimising it||2693|
|5,Implicitly minimizes/rejects AGW||49|
|6,Explicitly minimizes/rejects AGW but does not quantify||13|
|7,Explicitly minimizes/rejects AGW as less than 50%||8|
It is obvious that the figure of „97%“ of „scientists“ (what more exactly speaking must be „studies“) that support AGW is not realistic. When we set that „supporting“ studies are found only in group 1 to 3 and sum up these numbers we get a total 3601.
When the remaining groups are totaled we get 7391.
As a total of all studies this figure results in 10992.
So we can calculate that 32.7% of all examined studies support AGW to a more or less degree. On the other hand 67.2% don‘t. Having no opinion means that there is counted as NO SUPPORT entity. In addition only 7.7% of the examined stduies strongly support AGW theory.
Deducing that „97%“ of the >10.000 studies support AGW theory is faulty. Roughly about 30% state a support for AGC theory to a more less extent.
Coding of the software:
Dim strS0 As String Dim n(10) As Integer Dim T1, I As Integer Dim Z As Long Open "c:\cook\data2.txt" For Input As #1 While Not EOF(1) Line Input #1, strS0 Z = Z + 1 For T1 = 1 To 7 'Debug.Print "*" + Right$(strS0, 1) + "*" If Right$(strS0, 1) = Chr(T1 + 48) Then n(T1) = n(T1) + 1 End If Next I = I + 1 If (I > 1000) Then For T1 = 1 To 7 Debug.Print n(T1), Next Debug.Print " " I = 0 End If DoEvents Wend Debug.Print Z