Open AccessA Flood Damage Allowance Framework for Coastal Protection With Deep Uncertainty in Sea Level Rise
Author(s) -
Rasmussen D. J.,
Buchanan Maya K.,
Kopp Robert E.,
Oppenheimer Michael
Publication year - 2020
Publication title -
earth's future
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.641
H-Index - 39
ISSN - 2328-4277
DOI - 10.1029/2019ef001340
Subject(s) - allowance (engineering) , flood myth , damages , coastal flood , nuclear decommissioning , margin (machine learning) , risk analysis (engineering) , population , ignorance , range (aeronautics) , computer science , environmental science , environmental resource management , climate change , business , engineering , operations management , sea level rise , geography , geology , oceanography , archaeology , philosophy , law , aerospace engineering , waste management , sociology , epistemology , machine learning , political science , demography
Deep uncertainty describes situations when there is either ignorance or disagreement over (1) models used to describe key system processes and (2) probability distributions used to characterize the uncertainty of key variables and parameters. Future projections of Antarctic ice sheet (AIS) mass loss remain characterized by deep uncertainty. This complicates decisions on long‐lived coastal protection projects when determining what margin of safety to implement. If the chosen margin of safety does not properly account for uncertainties in sea level rise, the effectiveness of flood protection could decrease over time, potentially putting lives and properties at a greater risk. To address this issue, we develop a flood damage allowance framework for calculating the height of a flood protection strategy needed to ensure that a given level of financial risk is maintained. The damage allowance framework considers decision maker preferences such as planning horizons, protection strategies, and subjective views of AIS stability. We use Manhattan—with the population and built environment fixed in time—to illustrate how our framework could be used to calculate a range of damage allowances based on multiple plausible scenarios of AIS melt. Under high greenhouse gas emissions, we find that results are sensitive to the selection of the upper limit of AIS contributions to sea level rise. Design metrics that specify financial risk targets, such as expected flood damage, allow for the calculation of avoided flood damages (i.e., benefits) that can be combined with estimates of construction cost and then integrated into existing financial decision‐making approaches (e.g., benefit‐cost analysis).