With sea levels, rise the damage costs

According to a recent study, as the sea levels rise, the economic damage increases even faster.

The Potsdam Institute for Climate Impact Research (PIK) researchers now provides a method to quantify monetary losses from coastal floods under sea-level rise. For the first time, the scientists show that the damage costs consistently increase at a higher rate than the sea-level rise itself.

Lead author Markus Boettle said that the study illustrates that the complexity of climate change, adaptation and flood damage can be disentangled by surprisingly simple mathematical functions to provide estimates of the average annual costs of sea-level rise over a longer time period.

The scientists developed a method that translates the occurrence probability of flood events into the probability of inundation damage. Expected regional sea level rise is taken into account by separating two components, namely the increasing number of events and the increasing severity of each one. Moreover, potential flood defense measures like dikes or sea walls can be included into the calculations as they prevent or mitigate damages from storm surges.

Although coastal cities are different around the world and also flood-related threats have their own characteristics at different coasts, the scientists found general results. "Our equations basically work in Mumbai, New York, Hamburg - Pacific, Atlantic, or North Sea. In any location worldwide the same simple and universal expressions hold true," says co-author Jurgen Kropp.

Kropp noted that a large share of the world population lives in coastal regions. In the light of limited funds for adaptation it is an asset to provide comparable cost assessments. While mitigation remains of vital importance to keep climate impacts on a still manageable scale, an adaptation perspective can help to limit damage costs in the right places.

The study published in the journal Natural Hazards and the Earth System.