Warming and cooling of the Earths climate and their causes

The progressing wanning of the Earth's climate is mainly caused by natural factors, that is, the increasing solar activity and the decreasing volcanic activity on the Earth. The aspects which testify to the predominance o f natural factors include: synchronous changes in the average air temperature in the Northern Hemisphere in the years 1856-2002, the average consecutive 11-year Wolf numbers and the location of the mass centres o f the four largest planets. Natural causes o f the climate warming are corroborated by the synchronicity o f changes in the carbon dioxide concentration and paleotemperature in the last 450,000 years, revealed on the basis o f an analysis o f the ice core in Antarctica. Periods o f climate warming occur every 100,000 years and are caused by an increased solar radiation in high latitudes, resulting from changes in the Earth's orbit and the inclination of the Earth axis (according to the popular Milanković theory).