There is increasing concern among financial regulators that changes in the distribution and frequency of extreme weather events induced by climate change could pose a threat to global financial stability. We assess this risk, for the case of floods, by developing a simple model of the propagation of climate-induced shocks through financial networks. We show that the magnitude of global risks is determined by the interplay between the exposure of countries to climate-related natural hazards and their financial leverage. Climate change induces a shift in the distribution of impacts towards high-income countries and thus larger amplification of impacts as the financial sectors of high-income countries are more leveraged. Conversely, high-income countries are more exposed to financial shocks. In high-end climate scenarios, this could lead to the emergence of systemic risk as total impacts become commensurate with the capital of the banking sectors of countries that are hubs of the global financial network. Adaptation policy, or the lack thereof, appears to be one of the key risk drivers as it determines the future exposure of high-income countries. This implies in particular that the avoided costs in terms of financial stability should be weighted in as benefits of adaptation policy.

金融监管机构越来越关注由气候变化引起的极端天气事件的分布和频率变化可能对全球金融稳定构成威胁。对于洪水的情况，我们通过开发一个通过金融网络传播气候引起的冲击的简单模型来评估这种风险。我们表明，全球风险的严重程度取决于各国承受与气候相关的自然灾害的风险与其财务杠杆之间的相互作用。气候变化导致影响分配向高收入国家转移，因此随着高收入国家金融部门的杠杆作用增加，影响扩大更大。相反，高收入国家更容易遭受金融冲击。在高端气候下，由于总体影响与作为全球金融网络枢纽的国家的银行部门的资本相称，这可能导致系统性风险的出现。适应政策或缺乏适应政策，似乎是关键的风险驱动因素之一，因为它决定了高收入国家的未来风险敞口。这尤其意味着应将在财务稳定方面避免的成本作为适应政策的收益进行加权。