Welcome!

Thanks for visiting my page..

I'm a Lecturer in the School of Earth Sciences at the University of Bristol. Formerly of the GFZ Potsdam, Yale and Southampton University, I am an isotope geochemist, with wide-ranging scientific interests, but a particular focus on understanding modern biogeochemical carbon fluxes, Earth's long-term carbon cycle and the response of Earth's climate to changes in pCO2. I have done a lot of work in the development and application of geochemical proxies for past CO2 levels, ocean pH, and palaeotemperature, including the development and application of the boron isotope-pH proxy, as well as Mg/Ca ratios in calcite, foraminifera shell weight, foraminiferal fragmentation, and other geochemical proxies. Planktic foraminifera have been my archive of choice up to now, and through culturing, I've developed a keen interest in their physiology, ecology, and biomineralisation pathways. I'm a firm believer in the requirement to understand the biology and life processes of planktic foraminifera, both living and extinct, to quantify potential ‘vital effects’ that may interfere with recorded environmental proxy signals.

I'm currently PI of two DFG grants, one looking at the evolution of the global boron cycle over the past ~100 Million years, and one looking at potential for secular changes in the Earth's silicate weathering feedback to drive warming events- with the Middle Eocene Climatic Optimum the primary focus. I am also involved in two further DFG grants as part of the SPP2299, looking at the effect of bleaching on modern and fossil Eocene corals.

I'm also leading the PETRARCH project, which aims to detangle the specific abiotic and biogeochemical drivers that intersect to drive ocean anoxia. We'll be developing radiolarian silica as a new archive for boron isotopes, and combining this with established methods to use the Cretaceous Ocean Anoxic Events as useful case studies in how Earth crosses thresholds into profound global marine anoxia.

My research at Yale focussed on the Latest Cretaceous, K-Pg boundary and Earliest Cenozoic, a period of profound climatic instability and carbon cycle fluctuations, and one I started studying during my M/Sci project at the University of Bristol. Understanding the climatic effects of changes in atmospheric CO2 levels during this period can provide valuable insights into the sensitivity of the Earth system to pulses in greenhouse gas concentrations. Some outputs from this post-doc include this paper published in PNAS in late 2019, and this paper published in Science in early 2020. My move to GFZ Potsdam brought me more into the world of chemical weathering, and the interaction between plants, biota and the global silicate weathering feedback. At Bristol I'm enjoying the freedom to pull all of these types of research together, to try and keep a whole-Earth (not just marine or terrestrial) perspective on the Earth's carbon cycle. I work at the intersection between the Geochemistry, MATES and Palaeobiology groups, and am a member of the Bristol Isotope Group (BIG) and Bristol Oceans Past and Present (BOPP) Interdisciplinary Research Groups.

Besides publications I hope to keep this site updated with some useful links, R-code and datasets for people to use.. but you might also have more luck on my GitHub.. If you've got any questions, drop me a line at michael dot henehan (at) bristol dot ac dot uk.