Human Lives at Risk because of Eustatic Sea Level Rise and Extreme Coastal Flooding in the Twenty-First Century

Abstract

ea level rise (SLR) is a topic of increasing importance, as global warming continues to drive it at the global level and other factors such as land subsidence also affect it at the local level. Economic and human-based approaches have been taken to assess its impact on society. However, quantifications of the effect of SLR on mortality have not been extensive. Therefore, the objective of this study is to quantify the relative impact of SLR on mortality due to extreme coastal flooding for 2011?2100. First, an empirical relationship between annual storm surges caused by tropical cyclones (TCs) and associated fatalities is established. Next, a conceptual framework is introduced to measure rises in sea level due to gradual SLR and temporary storm surges on a common scale called cumulatively raised sea level. An analysis applying SLR projections to this framework shows that, in addition to the deaths that occur because of coastal flooding due to TCs, at least 84?139 deaths due to extra coastal flooding caused by SLR may occur in the United States by 2100, in the absence of coastal population changes, adaptation, and protection failure. Higher-than-expected rates of SLR due to increased discharge from polar glaciers will raise this estimate to 277. Protection failure will also result in more fatalities. Conversely, adaptation, even when combined with coastal population increases, may lead to fewer fatalities.