Celestial Climate Driver: A Perspective from Four Billion Years of the Carbon Cycle

My colleague and friend, Prof. Jan Veizer of the University of Ottawa, has written a review on the climatic role of carbon dioxide, cosmic rays and solar variability over different time scales. Unlike other material you will find on this web site, which was written with my subjective physicist's point of view, this review was written by one of the world's leading geochemists. As such, it can give the reader a complementary view.

Originally, Prof. Veizer set out to collect the most comprehensive geochemical data set, to reconstruct the paleoclimate variations over the Phanerozoic (the past 550 Million years over which there are multicellular fossils to work with). His goal was to find the climatic signature of carbon dioxide in the data. To his disappointment, there was no clear correlation between his paleoclimatic reconstruction and the CO2 reconstruction (e.g., Veizer et al., Nature, v. 408, 698, 2000). On the other hand, the reconstructed tropical temperature does seem to correlate well with the reconstructed cosmic ray flux, as obtained for example using Iron meteorites (e.g., read this for details). This led to a revolution in our understanding of climate drivers.

Here the review brought again for the public's interest (with permission of course).
Read and enjoy!