The 2024 Hans Oeschger Medal is awarded to Michael Sigl for his innovative contributions, which improved ice core chronologies and illuminated the impacts of volcanic eruptions on climate and societies.
Michael Sigl is an expert in using isotopic signatures to improve the accuracy of ice core chronologies. By synchronizing sulfate records from Antarctica and Greenland ice cores, he reconstructed past volcanic sulfur emissions and the associated climate forcing. Thereafter, comparison of ice core volcanic sulfate with annually resolved climate proxies, such as tree rings, confirmed unequivocally that large eruptions were dominant drivers of temperature variability on interannual to decadal time-scales for the past 2500 years. The accurate reconstruction of volcanic forcing is proving to be essential in untangling the multiple contributors to past climate variability. Anchored in a network of robust international collaboration that Sigl has fostered through his work, his accomplishments comprise a singular contribution to palaeoclimatology that will have lasting impacts.