The book is written on the basis of more than a dozen publications on the topic in scientific journals from 2004 to 2014 and contains 5 chapters in which the author successively sets out the energy basics of the formation of the temperature regime of surface air, describes the method of collecting data on the thermal regime, and sets out in detail the reasons for the heterogeneity long-term series of observations on a global network of meteorological stations. A review of historical information about warming and cooling and a description of glaciological observations of the behavior of glaciers is given. Conclusions based on a statistical analysis of numerous vectors of average annual air temperatures indicate the stability of climate and climatic norms in the 20th century, which is confirmed by comparing the map of isotherms of a hundred years ago, on which the annual temperature norm, equal to 0.50 ° C for Omsk, with the average long-term temperature, obtained in 2014 after extending the series by 100 years and equal to 0.5 °C. Adding temperature data for a hundred years of the 20th century to the short rows of the 19th century did not change the values of climatic norms.