Evaluation of storm surge flooding response to climate warming and sea level rise: A case study of Metro Manila, Philippines

Storm surge flooding induced by typhoons is among the most destructive coastal hazards worldwide. Under future climate warming and sea level rise (SLR), such events are expected to intensify, posing growing risks to coastal communities. However, knowledge of how warming and SLR may change typhoon-driven coastal flooding remains poorly quantified, particularly for the Philippines, a highly exposed region in the western North Pacific. This study applies a coupled atmospheric-hydrodynamic modeling framework to evaluate the response of storm surge flooding in Metro Manila to warming and SLR under SSP2-4.5 and SSP5-8.5 by 2100, taking Typhoon Nesat as a case study. To separate the impacts of different drivers, three experiments are conducted: (1) the warming-only case, (2) the SLR-only case, and (3) the combined warming + SLR case. Results indicate that Nesat-like events will produce higher storm surges and larger inundation extents by 2100, with the combined warming + SLR case yielding the most severe flooding. SLR is the primary contributor to the projected increase in flood hazard, while warming provides an additional but smaller effect for this event. These results provide one of the first SSP-based storm surge flooding projections for Metro Manila and support engineering-relevant planning for future coastal adaptation.