Avoiding severe impacts from anthropogenic climate change requires not only substantial reductions in greenhouse gas emissions but also further implementation of adaptation measures. In many regions with smallholder farming systems adaptation can help ensure food security despite significantly changing climatic conditions. However, the space for adaptation measures has limits. In this paper, we investigate hard and soft adaptation limits and discuss their relevance to food security in smallholder farming food systems. We argue that soft adaptation limits can be defined by (...) sufficiency levels of justice like basic needs, capabilities, human rights or levels of well-being. Depending on social, cultural, political and economic conditions different communities realize different sufficiency levels of justice. Furthermore, as normative claims of justice, these sufficiency levels not only allow the social, cultural and political and economic conditions of social systems to be described but also define entitlements. We show that for smallholder farming systems with low social and economic standards these entitlements might mean that soft adaptation limits can define entitlements to social and economic improvements despite transformational adaptation to changing climatic conditions. (shrink)

Climate change is widely recognized as a major risk to societies and natural ecosystems but the high end of the risk, i.e., where risks become existential, is poorly framed, defined, and analyzed in the scientific literature. This gap is at odds with the fundamental relevance of existential risks for humanity, and it also limits the ability of scientific communities to engage with emerging debates and narratives about the existential dimension of climate change that have recently gained considerable traction. This paper (...) intends to address this gap by scoping and defining existential risks related to climate change. We first review the context of existential risks and climate change, drawing on research in fields on global catastrophic risks, and on key risks and the so-called Reasons for Concern in the reports of the Intergovernmental Panel on Climate Change. We also consider how existential risks are framed in the civil society climate movement as well as what can be learned in this respect from the COVID-19 crisis. To better frame existential risks in the context of climate change, we propose to define them as those risks that threaten the existence of a subject, where this subject can be an individual person, a community, or nation state or humanity. The threat to their existence is defined by two levels of severity: conditions that threaten (1) survival and (2) basic human needs. A third level, well-being, is commonly not part of the space of existential risks. Our definition covers a range of different scales, which leads us into further defining six analytical dimensions: physical and social processes involved, systems affected, magnitude, spatial scale, timing, and probability of occurrence. In conclusion, we suggest that a clearer and more precise definition and framing of existential risks of climate change such as we offer here facilitates scientific analysis as well societal and political discourse and action. (shrink)