Professor Friedrich Karl Ewert advised in 36 countries on the construction of 83 dams. The geologist specializes in investigating the permeability of rocks and the methods of sealing them. Accurate measurements, precise statistical surveys were needed to rule out later shortcomings or even a disaster.

With this methodical thoroughness, he began to question climate change after retirement. He began to evaluate the temperature measurements of the usual warm and cold phases, as he had learned during his studies. Since 1880 there was already a worldwide network. The data thus obtained are managed by the Goddard Institute of Space Studies (GISS) of a department of NASA and offered on the Internet. Of the meanwhile 7365 stations, there are evaluable data series of 1153 stations for the period from 1881 onwards. These figures are also the basis by which NASA supplies the IPCC, the so-called IPCC. And from these publicly available data, Ewert has…