Severe flooding is likely to be common in the future – blame sea surges and heavy downpours

Finland is relatively well-prepared for the floods made worse by climate change, but this comes at a cost. In other parts of the world, entire villages in high-risk areas are already being relocated.

In Maija Vilkkumaa’s recent one-act play 'Marine Weather' (Finnish Merisää), southern parts of Helsinki are left underwater, and people get around the streets in rowing boats.

This nightmare scenario is not likely in the near future in Finland. Nevertheless, it is good to be prepared for any damage that might be caused by flooding.

Helsinki was hit by a record-breaking flood in January 2005, when the sea level rose 1.5 metres above its usual level. The sea was lapping onto the Market Square, and anti-flood barriers made of compressed paper bales were brought to the nearby Cholera Basin.

By the end of the century, something like this may even take place every other year, according to Havu Pellikka, a researcher in the field of geophysics.

In her doctoral thesis, Pellikka presents the predictions for rising sea levels in coastal Finland. The findings can be used by officials when assessing the limits to future construction along the shoreline.

Speed is key

Nothing dramatic is anticipated in Finland in the next few decades. Climate change will nonetheless spell the melting of the glaciers and rising sea levels, maybe even by several metres in the 22nd century. According to research, within the span of thousands of years, the complete exhaustion of fossil fuels will lead to a sea level rise of ten metres.

“In the long run, the sea level rise is going to change the world as we know it,” states Pellikka.

What matters is the pace of change. The rate at which the water level rises is more vital for adaptation than its eventual height. We can protect ourselves from floods if there is time and money.

“Slowing down climate change is the best form of adaptation. The more it’s mitigated, the less we have to adapt,” says Sirkku Juhola, a professor of urban environmental policy.

But adaptation is needed because change can no longer be avoided.

Rain and snow

When preparing for floods, short-term fluctuations should be taken into account. The wind might cause water to surge ashore. 

Besides coastal floods, Finland also experiences flash floods and river floods caused by the melting snow. These are also affected by climate change.

Climate change is heating up the atmosphere in a way which may increase the intensity of heavy rains. River floods on the other hand may decrease or occur earlier in the spring.

The capital region may experience more winter floods. That’s because snow and sub-zero temperatures will be replaced by intense rainfall that the damp soil is unable to absorb.

Finland has already experienced flash floods.

All sectors must prepare

“In the spring of 2019, an enormous flash flood in the Helsinki Railway Station brought all the station elevators to a halt for a lengthy period of time. In 2007 in Pori on the south-west coast stormwater flooding caused over 20 million euros damage,” says Karoliina Pilli-Sihvola, a senior auditor at the National Audit Office of Finland.

Pilli-Sihvola’s doctoral thesis was about disaster risk management and adaptation to climate change. According to Pilli-Sihvola, all sectors should prepare for the weather-related risks resulting from climate change. In addition to floods, both people and the environment are threatened by storms, heatwaves, drought and slippery conditions.

“Not a lot of industries are future-proofed against the effects of climate change. The most important way of adapting to climate change is to take it into consideration in all decision-making, for example, when drafting new building code and land use plans.”

Finland adapts

Finland is quite adept at risk management, according to Pilli-Sihvola, at least when compared to many other countries. It is prohibited by law to build on flood plains and the laws are usually followed. Neither of which is the norm on the global scale. 

Moreover, many preventive measures have been taken to stop flooding. For example, in the Jätkäsaari development in southern Helsinki, the ground level was raised before construction began. In East Helsinki landscaped flood barriers have been built and the Vauhtitie wetlands behind the opera house provide protection from stormwater.

Finland was the first European country to make a national adaptation plan in 2005. The plan is comprehensive and has been updated since, which means that, when compared to other EU countries, Finland is well prepared for climate change.

Municipalities and their residents

Yet the division of responsibilities is still quite unclear in Finland as well, according to Sirkku Juhola.

“What is a municipality’s responsibility if a building permit has been granted for a property which now experiences frequent flood damage?” ponders Juhola.

Juhola’s research group conducted a survey of all of Finland’s municipalities, to determine their strategies for adapting to climate change. It turned out that preparations had not been fully developed anywhere else than in the big cities. Municipalities have great autonomy, and whether any strategies are implemented is dependent on their willingness to prepare and available resources.

Since 2014, the government no longer offers compensation for damage caused by floods. Instead, it is the responsibility of the residents. Home insurance usually covers the expenses.

“While home insurance covers economic loss, many people may have the kind of property that simply cannot be reimbursed with money, such as photographs. That is why it would be important for people to be aware of the risks,” Pilli-Sihvola says.

At your own risk

According to Finland’s National Adaptation Plan, preparation is everybody’s responsibility. However, the plan does not clearly state what should be done. Juhola doubts that companies or citizens are fully informed about the situation.

“In my public lectures I sometimes ask the audience for a show of hands if they are aware that preparing for climate change is everyone’s personal responsibility. Usually, not a single hand goes up.”

The professor is not criticizing the adaptation plan’s policy in itself but the fact that it is so little known.

“How many people dreaming of a seaside property will have checked flood maps before making a decision to buy?”

A discount might work

Juhola and her associates have carried out a global comparison of 300 cities to see what carrots and sticks are being used to promote climate change adaptation. In addition to regulation, directives and information, several countries use economic incentives. According to Juhola, those could be used even more, and in Finland too.

In the USA and Denmark, for example, in some cities citizens can get reduced water bills if they cultivate green areas on their property to absorb urban runoff.

Sirkku Juhola is a member of the Finnish Climate Change Panel, which is a body of experts that provides reports and analyses. The Panel is currently examining how various means of adaptation used in other countries could be applied in Finland.

To move out or to dam

Throughout the history of humankind, cities have been built near waterways. The risk of flooding is present in 40% of the largest cities of the world, prompting many of them to be well prepared for the water level rise. For instance, New York and London have done a great deal, the professor reckons.

“In the worst-case scenario, people will have to move out, but an average rise in water levels can already be confined,” Juhola states.

Discussion as to whether some flood zones should simply be emptied took place in Central Europe and Britain. A decision to relocate the village of Fairbourne on the Welsh coast has already been made. A village in Alaska, threatened by climate change, is also being relocated.

However, Juhola doesn’t foresee a situation in Finland where living in a flood risk area would prevent people from getting insured or where entire villages would need to be relocated.

The poor suffer

According to Karoliina Pilli-Sihvola, it’s difficult to determine whether it is more efficient to prepare for the risks in advance or just deal with the situation as it arises.

If a weather event occurs very rarely it is cheaper to just fix the damage. On the other hand, taking the risks into account during construction is usually cheaper than doing so after the fact.

With money you can buy all kinds of flood protection. The Netherlands is a classic example of how it’s possible to live below sea level. After the Great North Sea flood of 1953 there have been major investments in dams and barriers.

The problem is that many poorer countries have neither the resources nor the legislation to prepare properly. In these cases, the only solution to rising water levels is to evacuate everything, people and property.

Pilli-Sihvola has worked in many countries, in which evacuation due to flooding is part of everyday life, for example in Myanmar, Malawi, Bhutan, and Zimbabwe.

“Poor countries are the most vulnerable when faced with climate change. That holds true for both floods and drought.”

Havu Pellikka agrees: “I am more concerned about the global situation than about Finland. In Bangladesh people are being displaced due to floods, and tiny island nations which are only a few metres above sea level, are drafting plans for evacuating the entire population.”

 

The article has been published in Finnish in the 09/20 issue of the Yliopisto magazine. It was translated by the following English philology undergraduates: Jonna Alahautala, Diana Belozjorova, Anna Hakala, Miia Hankonen, Joona Juselius, Miro Jääskeläinen, Elisa Kari, Elli Kähkönen, Okko Länsikunnas, Sebastian Sihvola, Kaung Thein and Henni Veikkonen. It was post-edited by John Calton, lecturer in English at the Department of Languages.

Where does the water go?

Sea levels don’t rise to the same extent in different regions of the globe. The rise in levels is influenced by ocean currents, water salinity and temperature, together with the distance from the polar caps.

Contrary to expectations, a melting ice sheet doesn’t raise the water level in its own vicinity. The mass of the ice sheet draws the seawater, with the surface of the water inclining towards the ice sheet. If the ice sheet melts, the attraction diminishes or disappears altogether. The melting of the continental iceshelf also causes land uplift.

Finland and the Baltic rim countries get off lighter than many other areas. As Greenland melts, the gravitational field in the northern hemisphere will change and the meltwater will flow south. If Antarctica melts, the repercussions for the north will be severe.

Finland is still helped by land uplift following the Ice Age. Over a century the land will rise by almost a metre in the Gulf of Bothnia and by about 40 centimetres in the Gulf of Finland. To some extent this mitigates the impact of a rise in sea level. Most vulnerable are the towns on the south coast.

Increased rainfall has no bearing on coastal flooding. The rise in levels in the Baltic is mainly through the Danish straits. However, heavy rainfall might gradually change the balance of salinity in the Baltic towards freshwater and freshwater is more expansive than salt water.

Predicting rises in sea level is not an easy task. Climate models model thermal expansion and the melting of ice sheets. The melting of the continental ice shelf is especially hard to predict.

“West Antarctic is particularly unstable. There may be rapid changes, and no one knows what will happen,” says Havu Pellikka, a geophysical researcher.