Permafrost landscapes and high northern infrastructure are under threat of erosion as a consequence of thawing permafrost across the Arctic due to a rapidly warming climate. The young investigator group PermaRisk aims to provide a novel approach for the simulation of erosion and mass wasting processes in permafrost landscapes under a warming climate. The project aims to deliver comprehensive risk assessments for Arctic ecosystems and infrastructure taking into account different processes of permafrost degradation. Current model approaches used to simulate the degradation of permafrost under a warming climate are highly simplistic since they only consider one-dimensional (top-down) thawing and ignore lateral processes such as soil erosion and mass wasting which are the most abundant form of thaw in many regions. Thus, current model assessments are most likely far too conservative in their estimates of permafrost thaw impacts. It therefore remains uncertain how climate warming and permafrost thaw will affect (i) the intensity of erosion and mass wasting processes and (ii) essential ecosystem functions, landscape characteristics, and infrastructure. It also remains unclear (iii) whether any erosion-induced landscape changes further accelerate permafrost thaw. In order to answer these critical questions, land surface models (LSMs) require a new level of realism in order to adequately project permafrost thaw dynamics. Within the PermaRisk project, the permafrost model CryoGrid3 will be extended with an erosion scheme that allows to represent lateral processes within the limited framework of one dimensional LSMs. The new concept will be applied and validated at three Arctic key sites in Alaska (Deadhorse/Prudhoe Bay), Canada (Arviat), and Siberia (Lena-River-Delta). Furthermore, 21st century climate impact projections for the key sites are scheduled as a basis for thorough risk analyses concerning potential damages to critical ecosystem functions and infrastructure for the three key sites. These risk analyses will focus on near-term impacts for the coming decades as well as on long-term consequences for end of the century.