Lynetteholm, an artificial island that has been approved to construct by the Danish parliament in 2021, is built near the Copenhagen sea to prevent the city from being flooded by the rising global sea levels due to climate change.

The global sea levels have been rising rapidly over the past 10 years. According to the European Environment Agency (EEA), in 2010, the global average sea level had increased 49.1 millimetres compared to figures in 1993.

However, in 2021, the rising rate had increased to 86.7 millimetres and reached its highest value ever, 103.1 millimetres, in 2023. It is predicted by the EEA that in 2070, the global average sea level will rise by nearly 500 millimetres. As a coastal city, Copenhagen is predicted to be one of the areas that will be affected by the global rising sea levels the most.

For that reason, to avoid Copenhagen from being flooded in the future, the Danish government raised the idea of building an artificial island near Copenhagen sea. In October 2018, the Danish government and the City of Copenhagen outlined an agreement to create Lynetteholm. In June 2021, the act of the construction of Lynetteholm was passed by the Danish parliament and will be constructed by the real estate company By & Havn, which marked the start of Lynetteholm.

According to Lynetteholm’s construction report from By & Havn, Lynetteholm, the artificial island built between Refshaleøen and Kronløbet in Copenhagen, has a total area of 275 hectares. The outside edge of the island mainly consists of large rock dams, which are built of sand and rocks. After the construction of the island’s outside edge is finished, surplus soil from construction projects in and around Copenhagen will be reused to fill inside for storm surge protection.

The project is expected to cost 4.214 billion DKK in total. According to By & Havn, the construction of Lynetteholm is expected to finance itself, “soil being used to fill into the perimeter is from contractors, developers, and others who want to get rid of soil from their construction projects in Copenhagen and surrounding areas.”

“Meanwhile, the sale of planning rights from the urban development of Lynetteholm will also generate income to co-finance the metro service that will link Lynetteholm with other parts of Copenhagen. This means that the construction of Lynetteholm as a peninsula and storm surge protection is economically self-sustaining,” said By & Havn.

“The Lynetteholm project is aimed at solving four overall challenges for the city of Copenhagen, storm surge protection, need for more housing, congestion both for road traffic and public transportation, and creating space for soil landfill,” said the Copenhagen City Hall.

“Copenhagen will be more exposed to storm surges in the future, which can cause major damage to houses and trains. Lynetteholm can protect the city from storm surges from the north.”

The Copenhagen City Hall also said Lynetteholm is an opportunity to create space for more people in Copenhagen in the future, “by 2060, around 120,000 more people will live in Copenhagen. Once the construction of Lynetteholm is fully completed in 2070, more housing and workplaces can be provided to 35,000 people in Copenhagen. With more housing from Lynetteholm, it will lower the increase of prices in the housing market and create housing for more people without housing prices skyrocketing.”

It seems that the construction of Copenhagen is bringing a lot of benefits from different aspects to the locals in Copenhagen, but Lynetteholm has been surrounded by concerns and controversies since the start of its planning stage. Different non-governmental organisations have been questioning the negative impacts Lynetteholm’s construction would have on the Baltic Sea, where Lynetteholm is constructed very close to.

Christina Ihler Madsen from Climate Movement in Denmark, one of the non-governmental organisations that openly opposes the idea of building Lynetteholm, said the construction has become such a huge controversy topic in Denmark not only because it is the biggest ever building project in Denmark, but also because concerns about the climate and environment have been ignored since the first time Lynetteholm was presented in 2018.

“Lynetteholm has no positive environmental impacts that I am aware of. Other than damaging the marine environment of the Baltic Sea, the climate will also be impacted, both because of construction and marine-life effects,” said Madsen.

“The blockage of the ‘Kongedybet’ underwater channel is a severe risk to the Baltic Sea. Being blocked by Lynetteholm, Kongedybet will not be able to provide fresh sea water to the Baltic Sea. Without fresh sea water, marine lives in the Baltic Sea will be disrupted,” he said.

In 2021, believing the government had concealed the major climate and environmental impact from the public, Climate Movement in Denmark wrote a complaint to the EU Parliament’s Committee for Petitions to demand a climate and environmental assessment of the entire project as required by the EU law.

However, the complaint was later on rejected by the EU Commission as the Commission believed that the decision about a potential legal breach was a matter for the Danish judicial system.

Kristen, a local Dane who works in a restaurant nearby the construction of Lynetteholm, believed that Copenhagen does not need the island due to the damage it has caused to the environment. “We are building it (Lynetteholm) to prevent ourselves from being damaged by the climate, but we are damaging the environment at the same time. I think we need more housing for people to live in, but I do not think that is the best idea,” she said.

When asked about the controversies and concerns about Lynetteholm, By & Havn said the project has already went through an environmental assessment revived by Østre Landsret before being politically approved, “there is no reasonable basis for claims that Lynetteholm’s construction would cause significant environmental harm to the Baltic Sea or the project was approved in violation of international consultation rules.”

The City of Copenhagen also replied the possibility of blocking the flow of water and salt in Øresund have been assessed by the Danish Hydraulic Institute, “in their environmental impact report for the construction of Lynetteholm, the blocking factor is rated up to 0.25% for water flow and 0.23% for salt in Øresund, which is assessed to be “none/negligible” in the environmental impact report.”

“Also, Kongedybet is not the only underwater channel the Baltic Sea has to exchange for clean water. The exchange of water also takes place through Lillebælt, Storebælt and Øresund. Therefore, it is only 0.07% of the 0.25% for the water flow blocking factor that has consequences for the Baltic Sea,” they said.

To make amends to the possible damage to the environment, the City of Copenhagen said By & Havn will work to plant eelgrass to compensate for what will be removed because of the construction of Lynetteholm, since 2 to 4 hectares of eelgrass and other vegetation on the bottom of the sea are expected to be covered by Lynetteholm.

“The establishment of new eelgrass will create new habitats for animals and plants below the surface of the sea. Also, a marine park will be established that will create new habitats for animals and plants below the surface of the sea and strengthen the biodiversity in the area around the construction of Lynetteholm,” they said.