Cosmic rays and the biosphere over 4 billion years



Variations in the flux of cosmic rays (CR) at Earth during the last 4.6 billion years are constructed from information about the star formation rate in the Milky Way and the evolution of the solar activity. The constructed CR signal is compared with variations in the Earths biological productivity as recorded in the isotope δ13C, which spans more than 3 billion years. CR and fluctuations in biological productivity show a remarkable correlation and indicate that the evolution of climate and the biosphere on the Earth is closely linked to the evolution of the Milky Way. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)