Wahl & Amman are collaborators with Mann, et al. They can hardly be considered neutral.
A number of researchers have reported “hockey sticks,” but the methodology which Jones used to produce the hockey stick for the WMO cover was simple fraud. No honest paper validates splicing measurement data in place of reconstruction results, to hide the falsification of their reconstruction method: the fact that, where measurement data is available to check the reconstruction results, they do not match.
