Scientists at NILU have analysed how vulnerable the Norwegian economy and business sector will be in the event of an increasing number of flood events. In the future, we may have storm surges that are three times more destructive than the worst events today.
Norway has the world’s second longest coast, according to the Norwegian Mapping Authority, over 104,000 km. This makes us extra vulnerable to rising sea levels and storm surges.
“Due to climate change, sea level may rise. Then high tides and storm surges will occur more often than today, and flood events will be more severe, says scientist Francis Barre in NILU’s Department of Environmental Impacts and Sustainability.
He is the lead author of a recently published scientific article in Environmental Research Letters. The article is an analysis of how exposed Norwegian municipalities and local businesses are in terms of increased risk of storm surges.
Storm surges occur when the water level becomes extra high due to the influence of weather. This is usually due to low air pressure and strong winds that push the water towards the coast. Not all municipalities have the same exposure to storm surges. Ålesund, Tromsø and Bergen are among the most exposed cities in Norway.
Three times more destructive
“Today, we see that 0.2% of the economy is exposed in the event of a 20-year storm surge, i.e. a storm surge of a magnitude that will occur on average every 20 years. At a much rarer magnitude like a 1000-year storm surge, 0.4% of the economy will be exposed, Barre says.
However, with continued greenhouse gas emissions and subsequent climate change, sea levels may rise. Then there will be large storm surges more often than there are now. The NILU researchers have used the expected sea level in the year 2100 in a high-emission scenario.
“If emissions continue to be high, a storm surge that is at least three times more destructive than the rarest and worst one we see today will become a frequent occurrence,” Barre said.
The researcher adds that this does not necessarily mean that the consequences of climate change will be dramatic, but that prevention and adaptation to the new risks are needed.
“We see clear threshold and tipping point effects when the water level exceeds infrastructure built with outdated assumptions,” says Daniel Dean Moran, a senior scientist at NILU.
Includes all organizations
“The current economic impact assessment tools for studying this are either too broad or too narrow. They either look at national averages or very specific scenarios. They may be limited in geographical resolution or lack sector divisions”, the scientist explains.
To more accurately characterize national physical climate risk, NILU has developed a point-level map of employment and GDP that includes every single organization in the country.
“We can overlay this new economic map with flood scenarios maps from the Norwegian Mapping Authority , and thus see more clearly how the Norwegian economy is affected,” says Barre.
By using public business register data, the scientist can see how production, both private (companies) and public (schools, hospitals), contributes to local employment and national GDP, and thus he can analyse how much of GDP and jobs are exposed to different flood events, and which sectors are most exposed.
“This is a long-term challenge that Norway has to some extent ignored – so this work is very welcome,” says sea level scientist at the Norwegian Mapping Authority, Matthew Simpson, who has contributed to the project.
The project is supported by the Research Council of Norway and carried out in collaboration with scientists from the Norwegian Mapping Authority and NTNU.
Indirect exposure
“Our goal is to understand how exposed the Norwegian economy is to extremely high tides such as storm surges, and how much worse it can get with climate change. We hope both municipalities and businesses can benefit from this when planning and preventing,” says Barre.
Not all companies and organizations affected by the floods are necessarily located in the flooded areas. When one company is directly affected, it can affect the entire value chain such as partners, customers and suppliers.
“Because we include supply chains, we can see that indirect effects can be just as high as direct ones. Even sectors that are not located in flood areas are affected,” says Barre.
The water level is already affected
The results of the report “Sea-Level Rise and Extremes in Norway” from the Norwegian Climate Services Centre and the Nansen Centre in 2024 show that sea level rise is already affecting water levels in some parts of the country, especially in Western and Southern Norway.
“Due to global warming, Norway is in the process of going from being a country with an average falling or stable sea level to a country with a rising sea level. The higher the warming, the faster the sea level rise, and more of the country will experience net relative sea level rise,” the report’s summary reads.
The report shows that there are small differences (0.3 to 0.6 m depending on location) between water level levels that occur annually and water level levels that occur on average every 200 years. Sea level rise could lead to historically rare sea levels being reached more often, even annually or even more often in the future.
“Our new model shows the relationship between these physical climate risk scenarios and economic exposure,” says Moran.
Here you can explore the map with the economic model yourself: https://apps.sustainability.nilu.no/activitymap-no/
See also this interactive explainer feature https://activity-storymap-phd-francis-37cf69f2002379f19e3b612e06d3d00bc.pages.nilu.no/ for more information