At the start of august, Eastern-Norway was hit by extremely heavy rainfall. A very unusual event as this region does typically not experience any such heavy precipitation, nor to such a geographical extent.


The amount of precipitation accumulated over a couple of days surpassed the amount expected once every 100 years. The consequences of the storm impacted not only the areas hit by extreme downpour, but also areas downstream along some of Norway’s major rivers. The latest reports estimate damages of about EUR 150 million, not including the widespread destruction of roads, railways, and other infrastructure.

Accumulated precipitation from 8-10th of August 2023 (c) Meteorologisk Institutt
The lacking adaptation was highlighted before-hand

In 2022, the Office of the Auditor General of Norway (Riksrevisjonen) assessed that the Norwegian government does not have the necessary understanding of the risk of natural disasters in a future climate.


As it is a objective for the country to be prepared for and adapted to climate change, the past weeks have shown just how right the Auditor General was.

It is a fact that the number of buildings within mapped hazard zones will increase as a result of climate change. We also know that the existing built-up areas are not adequately protected from the effects of future climate change, and that we do not have an overview of the transport infrastructure’s vulnerability to future climate change among others. The Norwegians need knowledge, yes, but they also need action.

Critique of lacking climate adaptation 2022 (c) NRK

Even though the national government launched a plan for climate adaptation before the summer, there were more investigations planned than specific measures. Is the storm Hans the wakeup call Norway needs to start acting?


Could Hans be a Copenhagen moment?

The Copenhagen wakeup call was a consequence of 90,000 insurance claims following a terribly wet summer day in 2011. In the wake of the historic flooding, national government changed regulation, cities made adaptation strategies, water utilities rolled out huge investment plans and privates sought to future proof their homes.


What valuable lesson does the Copenhagen experience provide the Norwegians?

City of Copenhagen (2012): Cloudburst plan

Up to 135 mm of rain fell over the Danish capital on July 2nd, 2011. That is equivalent to almost two months’ of average precipitation. While the meteorological services had sent out warnings during the day, the city’s infrastructure and authorities as well as businesses and inhabitants were by no means prepared for an event of this magnitude. Damages where widespread and included:

  • Heavy disruptions of traffic due to flooded tunnels, train stations, and eroded embankments
  • Extensive loss of power and district heating
  • Flooding of IT equipment impacting police, public transport service and even prison communication and safety operations
  • Several hospitals on the brink of evacuated


However, most visual to the public eye where the vast damages to properties leading to almost EUR 1 billion in insurance payouts; making the flooding the costliest weather event in Europe that year.

A cloudburst tunnel in Copenhagen (c) HOFOR
Hundreds of initiatives

Copenhagen adopted a flood service level to guide future resilience work and let everyone in the city know what could be expected. More specifically the politicians pledged to design the city, so more than 10 cm of street level, standing water would only occur once a century statistically speaking even considering the effects of a changing climate on rain patterns.


This kind of ambition would require great investments and a mix of heavy engineering and softer solutions.


One of the main actors in adapting the city space is the municipal utility company. Since 2011, the utility has invested billions in upgrading the urban water infrastructure. Examples include cloud burst tunnels with diameters of 2,5 m and turning hard city surfaces into green water storage. Towards 2035, almost two billion EUR will furthermore be invested in a new batch of 350 climate adaptation projects.


Time will show how the storm Hans will affect the Norwegian action towards adaptation. What we have learnt from Copenhagen is that it will take time, resources and dedication, and despite more than a decade of action, Copenhagen has a long way to meet its objectives of creating resilient city.