Changing hurricane tracks and long-term flood risk insurance

The problem:
An approach for long-term flood risk insurance that would enable a feedback link from insurance providers to insurance clients and make it more attractive for the latter to increase the safety of their buildings needs to account for long-term changes in U.S. hurricane landfall statistics. We have shown that current ways of characterizing and assessing U.S. hurricane landfall risks are insufficient given possible but currently unknown impacts of global warming on hurricanes) and Atlantic multidecadal variability entailing periodic increases of up to 100% in major hurricane landfall risk.

The research:
Using GIS, we have begun to evaluate multidecadal variations in hurricane tracks along the Northeast coast. In the new Center, we will:

  1. use a simple algorithm to estimate landfall probabilities from the larger set of hurricane tracks in proximity to the Northeast coast (rather than just landfalling hurricanes); and
  2. extend this evaluation to other regions to produce risk maps and regional return periods that differentiate between different regimes of activity.

Grossmann is also working with The Tropical Meteorology Project of Colorado State University on the robustness of multidecadal variability in Atlantic hurricanes and other climate parameters prior to 1850. Currently, available hurricane and ocean data span only two oscillations of the multidecadal pattern. By extending these data, our analysis should enable more confident and accurate projections of future hurricane activity that can be used as a basis for long-term flood risk insurance approaches. A simple statistical model to test the existence of a global warming signal in Atlantic hurricane data has been developed in collaboration with CMU’s Department of Statistics. The interpretation of hurricane data and projections of changes in hurricane activity due to climate change are currently hindered by the considerable temporal inhomogeneities introduced into the data by far-reaching changes in hurricane observation technologies over time. We plan an expert elicitation to better assess the extent of these inhomogeneities.

The decision makers:
Florida International University (FIU),Florida Power and Light (FPL),IRGC,Munich Re, NRDC, and an indication from the National Hurricane Center of a willingness to share data.