The study of the climate system and the land carbon cycle is a topic that I can devote all my energy to. Understanding the impacts of global environmental change on land ecosystems is of greatest interest to us here on Earth and has captured my personal interest. I have been drawn to the use of numerical models representing Earth System functioning through my work with Fortunat Joos at Climate and Environmental Physics, University of Bern and now with Colin Prentice at Imperial College London.
I have been investigating a variety of processes of biosphere-climate interactions. In a study emerging from my Ph.D., we investigated how soil emissions of nitrous oxide and methane accelerate man-made climate change and how the strength of these feedbacks compares to other feedbacks in the climate system. This was the first consistent and comprehensive quantification of land- climate feedbacks with a coupled Earth system model.
Lately, I developed a new model to predict the spatial distribution of peatlands based on climatic conditions, vegetation productivity, and the local topography. Peatlands store vast amounts of carbon - almost the same amount as is presently in the atmosphere in the form of CO2. A predictive peatland carbon cycle model has long been missing and this has limited our understanding of how peatlands have contributed to CO2 changes in the past and may contribute to man-made climate change in the future. In order for our model to fill this gap, I freely provide the model code on my github site.
There are many more fascinating questions related with the biosphere and the Earth system. This one has captured my interest early on and was the starting point of my research: When in the past have human activities amounted to a scale large enough to leave its imprints on the atmospheric CO2 record? The question tackles the (in-)famous Early Anthropogenic Hypothesis which claims that early agriculturalists' deforestation and soil cultivation have caused the reconstructed sudden rise in atmospheric CO2 after 7000 years before present. Although this hypothesis has become hugely popular, we concluded that it just doesn't add up.
In the meantime, I’ve continued improving how land use change can be represented in global vegetation models and contributed results to the IPCC and (year after year) to the GlobalCarbonProject.