https://doi.org/10.5194/nhess-2020-44 Preprint. Discussion started: 26 February 2020 c Author(s) 2020. CC BY 4.0 License. Anthropogenic climate change and glacier lake outburst flood risk: local and global drivers and responsibilities for the case of Lake Palcacocha, Peru Christian Huggel1, Mark Carey2, Adam Emmer3, Holger Frey1, Noah Walker-Crawford4, Ivo Wallimann- 5 Helmer5 1Department of Geography, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland 2Robert D. Clark Honors College and Environmental Studies Program, University of Oregon, USA 3The Czech Academy of Science, Global Change Research Institute, 603 00 Brno, Czech Republic 4Department of Social Anthropology, Manchester University, UK 10 5Environmental Humanities; Department of Geosciences, University of Fribourg, Switzerland Correspondence to: Christian Huggel (
[email protected] ) Abstract. Evidence of observed negative impacts on natural and human systems from anthropogenic climate change is increasing. However, human systems in particular are dynamic and influenced by multiple drivers, and hence identifying an anthropogenic climate signal is challenging. 15 Here we analyze the case of lake Palcacocha in the Andes of Peru which offers a representative model for other glacier lakes and related risks around the world because it features a dynamic evolution of flood risk driven by physical and socio-economic factors and processes. Furthermore, it is the object of a prominent climate litigation case where a local Peruvian citizen sued a large German energy producer over risk of flooding from lake Palcacocha. Adopting a conceptual model of cascading impacts and multiple drivers of risk we first study climatic and other geophysical 20 drivers of flood risk.