EGU Milutin Milankovic Medal 2012

Wolfgang Berger is one of the most prominent scientists in modern Earth science. He has been pivotal in bringing Earth science up to its modern integrative and quantitative level through integrating concepts and thinking from geology, physical oceanography and chemistry of the ocean. His work is extensive, curious, intellectually stimulating and innovative and it covers an impressively wide range of marine sciences with an emphasis on understanding the operation of the climate system through studies of past climate changes. In addition he has made a particularly outstanding career in outreach and scientific communication by explaining scientific thinking, scientific concepts and results to all sorts of audiences from children to policy makers through books, lectures and essays. An aspect that is of particular value for the Milankovich award are his numerous contributions to understanding climate cycles and the development of our understanding of the imprint of orbital forcing on marine sediment. Berger is a pioneer in understanding the mechanisms of how the carbonate system of the ocean controls atmospheric CO₂ content and how the imprint of carbonate dissolution cycles can be read and understood by studies of the marine sedimentary record. He pioneered key concepts in this field for instanceby introducing the concept of the carbonate lysocline. These studies now serve as the backbone for modern studies of the threats imposed by ocean acidification. As part of this Berger also produced ground-breaking studies in the field of isotope geochemistry on the application of O-isotopes as palaeo-thermometers and C-isotopes as tracers of ocean nutrient cycles and ventilation. Berger immediately understood the importance of the ice core CO₂-record when it was first published and has provided some of the key references to our understanding of how the ocean must control atmospheric CO₂-levels, e.g. by introducing the Coral Reef Hypothesis which continues to be one of the main hypotheses in the on-going scientific debate on natural changes in atmospheric CO₂ content. Through his work on marine sedimentation and processes Berger has always been aware of the insight these records provide on various climate forcing factors. He has produced numerous papers investigating properties of orbital cycles, and the development of feedback processes driving the sensitivity of the climate system to orbital forcing, also including other parameters such as the imprint of lunar cycles into climate records. In this respect his contributions are truly an extension of Milankovich´s own work.