Comment on “Flooding Is Not like Filling a Bath” by Sanders et al.

Abstract In their commentary “Flooding is not like filling a Bath” in Earth's Future ( https://doi.org/10.1029/2024EF005164 ) Sanders and colleagues highlight biases and uncertainties in the application of bathtub modeling for assessing flood risks, specifically for coastal assessments at broad scales (world‐regional to global scales). This is a laudable and timely undertaking. Sanders et al., however, also draw a number of far‐reaching conclusions including a general call to abandon the bathtub model together with a claim that the bathtub model introduces unacceptable levels of uncertainty, and that its broad scale applications have contributed to a “climate hype” exaggerating the impacts of climate change. In our opinion, these conclusions are misleading and don't follow from the author's analysis, because the authors take an overly narrow perspective on flood risk. Addressing this issue, this comment characterizes the system problem of assessing current and future coastal flood risk at broad scales, discusses the roles that bathtub and physics‐based models play in addressing this problem, as well as the implications for communicating and receiving information on future flood risk at broad scale. Three conclusions are drawn. First, there is no one‐size‐fits‐all model for assessing coastal flood hazard at broad scales and the bathtub model and its variants still have a role to play. Second, physics‐based models are computationally too expensive to deliver the multitude of simulations needed for future flood risk and adaptation. Third, future work needs to create a framework to most effectively utilize physics‐based models, emulators of them and bathtub‐based models for broad scale assessments.