Damages from extreme events like floods are even more relevant than the mean sea level itself when it comes to the costs of climate impacts for coastal regions. However, while it is now rather well understood how sea-levels will rise in the future, only small progress has been made estimating how the implied damage for cities at the coasts will increase during the next decades. A team of scientists from the Potsdam Institute for Climate Impact Research (PIK) 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.
“When sea levels rise, damage costs rise even faster, our analyses show,” explains Markus Boettle, lead author of the study published in the journal Natural Hazards and the Earth System. Rising sea levels as a major impact of climate change pose a risk for coastal regions – the mean regional sea level rise takes effect by more frequent and more intense coastal flood events.
“At the same time, the severity of flood impacts is not only determined by environmental factors, but also to a significant extent by human decisions: flood defense measures can counteract the increasing flood risk,” says Boettle. “Our 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.
+++Flood risks, damages, adaptation+++
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 Jürgen Kropp, deputy chair of PIK research domain Climate Impacts & Vulnerabilities. For an exemplary implementation of their method, the scientists applied it to the city of Copenhagen in Denmark: They found that a moderate mean sea level rise of 11 centimeters until mid-century would in the same period double economic losses in this city, given no action is taken.
“A concise assessment of potential economic consequences is indispensable for appraising the efficiency of adaptation measures,” explains co-author Diego Rybski. “Even when temperatures stabilize, sea levels will continue to rise and shape our coastlines for future generations. So, additional preventive measures need to be considered in addition to the mitigation of greenhouse gas emissions, to help coastal regions especially in transition and developing countries to adapt and to limit damage costs.”
+++A large share of the world population lives in coastal regions+++
Nevertheless, some constraints of the methodology remain, which was developed in the broader context of the European-funded RAMSES project. For instance, extreme events and attributed damages are not evenly distributed in time – there are years without any damage at all and others when quite unlikely floods may occur. The approach cannot forecast single events and associated damages, but estimates damage expectations over longer time-spans. Despite of the lack of knowledge regarding the timing of the extreme events, the statistical spreading of damage over years has been quantified by the researchers.
“A large share of the world population lives in coastal regions,” says Jürgen Kropp, director of the RAMSES project. “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."
Article: Boettle, M., Rybski, D., Kropp, J.P. (2016): Quantifying the effect of sea level rise and flood defence – a point process perspective on coastal flood damage. Natural Hazards and Earth System Sciences.
Weblink to the article once it is published: www.natural-hazards-and-earth-system-sciences.net/index.html
Weblink to RAMSES project: www.ramses-cities.eu
For further information please contact:
PIK press office
Phone: +49 331 288 25 07
Jonas Viering | Potsdam-Institut für Klimafolgenforschung
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences