Anthropogenic climate change and glacier lake outburst flood risk local and global drivers and responsibilities for the case of lake Palcacocha, Peru

摘要

Evidence of observed negative impacts on natural andhuman systems from anthropogenic climate change is increasing. However,human systems in particular are dynamic and influenced by multiple driversand hence identifying an anthropogenic climate signal is challenging. Here we analyze the case of lake Palcacocha in the Andes of Peru, whichoffers a representative model for other glacier lakes and related risksaround the world because it features a dynamic evolution of flood riskdriven by physical and socioeconomic factors and processes. Furthermore, itis the object of a prominent climate litigation case, wherein a local Peruviancitizen sued a large German energy producer over risk of flooding from lakePalcacocha. Adopting a conceptual model of cascading impacts and multiple drivers ofrisk, we first study climatic and other geophysical drivers of flood risk. We find that an anthropogenic signal from flood risk to greenhouse gasemissions is traceable. In parallel, flood risk has been strongly shaped(and increased) by interacting socioeconomic, institutional and culturalprocesses over the past few decades. The case raises important questions about the differentiation ofresponsibilities relating to flood risk of both global and local agents, whichare, however, difficult to address in cases like Palcacocha, where we reveal a complexnetwork of interlinked global, national and local drivers. Following fromthis, we outline a normative framework with a differentiated perspective onresponsibility, implying that global emitters commit to supportstrengthening capacities in affected regions and localities and that localinstitutions and societies engage in local risk reduction measures andpolicies in collaboration with and driven by local communities.