Long-term solar activity the controlling factor in the 20th century global warming

The best-known proxy for changes in solar activity, such as cosmogenic isotopes: 14C and 10Be, are considered. From the analysis of these data the long-term cyclicity of solar activity of approximately 90 and 210 years is established. It is shown that widespread climatic changes, as coolings and warmings, may be the result of such effect in the past millennium. It is expected that a recent warming could emerge from the superimposed influence of the 90 and 210 years solar cycles on the climate system which is characterized by nonlinear dynamics.