Advanced climate models
The research was recently published in Earth's Future. The researchers used several global climate models. "Our research contributes to a better understanding of how storm surges can affect coastal areas in the future," says Sanne Muis. We developed storm surge forecasts from 1950 to 2050 using the latest CMIP6 climate projections from the Intergovernmental Panel on Climate Change (IPCC), United Nations. “We did this by forcing the Deltares Global Tide and Surge Model (GTSM) with several climate models from the High Resolution Model Intercomparison Project (HighResMIP),” Muis explains. Compared to the resolution of the regular CMIP models (100-200 km), the HighResMIP models are much more detailed with a resolution of 25-50 km. "The use of advanced climate models at high resolutions allows us to capture changes in storm patterns that were previously inaccessible. While there are still many open questions, this work represents a major leap forward and provides insight into how different regions with changing storm surge patterns due to climate change. This is valuable information for communities, governments and organizations as they make informed decisions about coastal development, disaster preparedness and resilient infrastructure.” said Muis.
Past versus present
The validation over the period 1985-2024 shows that there is a good agreement between the model output and the actual weather data. But the validation also shows that there are also large spatial distortions, indicating that the climate models do not accurately represent storm patterns in these areas. Using historical data from 1951-1980, the study compares predicted storm surge levels for the period 2021-2050. These results show that changes can occur up to 20% of the storm surge levels that occur on average once every 10 years.
There is a lot of variation in these changes around the world. Storm surges could become lower in some areas, such as the Mediterranean, North Africa and South Australia. In contrast, storm surges could be higher in other areas, such as Alaska, the Northern Caribbean, East Africa, China and the Korean Peninsula. These are only small changes compared to the large climate variability, uncertainties in the analysis of extreme values and model errors. Further research is necessary to gain better insight into the causes of model distortions and specific causes of the storm surge changes.