River deltas have grown over past 1000s of years and created hotspots for human civilizations to flourish. But, natural delta growth leads to a physical tipping point, after which follows evitable decline and land loss. In this project I will simulate how river sediments, sea-level rise, and human activities have formed deltas worldwide, from 12,000 years ago all the way into the future to 2300AD. I will estimate how close we are to this tipping point that will initiate dramatic loss of land, and evaluate the effect of human adaptation strategies to increase delta resilience.

Calcium carbonate minerals derived from the shells of planktonic organisms, cover most of the seafloor and act as a giant antacid tablet protecting the oceans against acidification caused by massive CO2 emissions. Here we find that microbes living at the seafloor are likely causing a lot of dissolution of these calcium carbonate minerals in the ocean. We also find that the shells of abundant gastropods named “sea butterflies” are protecting other, less soluble shells against dissolution. Thus, better understanding the ecology of these faunas is capital to accurately predict the response of the Earth System to current climate change.

Debris flows are fast-moving landslides that can devastate people and property. In many regions they interact strongly with vegetation, but how this affects their hazardous impact is surprisingly poorly understood. I will develop innovative experimental techniques using live seedlings and 3D-printed trees, to systematically quantify debris flow – vegetation interactions for the first time. This work will demonstrate how we can use vegetation to minimize debris-flow hazards, and provides the scientific foundation for anticipation of debris-flow hazards as a result of changes in vegetation caused by wildfires, deforestation, forest diseases, and climate change.

Models show that vegetation patterns may tell us about the health and fate of dryland ecosystems. This entails immense potential to evaluate and predict land degradation, one of the main environmental problems worldwide. However, these models often lack empirical validation of their outputs and of the mechanisms behind pattern formation. This research will study for the first time if such potential is supported by coupled empirical-modelling experiments.