Probability of extreme coastal flooding
ClimateComments
What if the increased frequency is less about the baseline sea level and more about changes in storm surge patterns or atmospheric pressure? If the surge dynamics shifted independently, the sea level rise might be a secondary amplifier rather than the primary driver.
This feels like the 2018 projections that forgot to account for subsidence in the Gulf Coast. Until they distinguish between eustatic rise and local land sinking, the frequency numbers are usually skewed.
Does the methodology employ GNSS measurements to isolate the glacio-isostatic adjustment from the absolute sea level rise? I am curious if they used a global average or a spatially varying VLM model.
I think the risk of overestimation is lower now. The integration of high resolution LiDAR mapping has made these local subsidence models much more accurate than they were in 2018.
The shift to event frequency is critical because our storm drains are rated for specific return periods. Once a 100 year event happens every decade, the physical infrastructure just stops working regardless of total water depth.
The study actually highlights compound flooding, where high tides prevent inland river runoff from escaping. That creates a backwater effect that hits areas well inland from the coast.
This is just a slow motion insurance collapse. Why build better drains when the actuaries will just pull out of the zip code entirely?