The 360-degree turn towards sustainability in Lahti
Nainen soutaa Vesijärvellä

The 360-degree sustainability transformation of Lahti

The journey of becoming
the European Green Capital 2021 – and

Photos: The City of Lahti and the photo archive of the Lahti City Museum.

Lahti ennen 1975


A city of heavy industry

The story of Lahti is closely linked to the development of Finland: An era of rapid growth and urbanisation that placed a burden on the environment continued until the 1970s. Lake Vesijärvi was one of the worst polluted lakes in Finland, and most of the jobs in the area were industrial, which later resulted in heavy unemployment during the recession.

Vesijärven historiakuva


The City stops discharging wastewaters into Lake Vesijärvi

Lahti already started ambitious water conservation work in the 1970s, with the aim of stopping the visible eutrophication of the largest lake in the city. Starting from 1976, the wastewater that used to go straight into Lake Vesijärvi has been treated at the Kariniemi wastewater treatment plant, from which the clean water is discharged into the Porvoonjoki River.

Kalastaja Vesijärvellä


The Vesijärvi I project starts

The journey of Lahti towards becoming a Green Capital started with the conservation of Lake Vesijärvi. The Vesijärvi I project was the largest restoration of a food web in the world: more than one million kilos of roach was removed from the Enonselkä Basin in the lake and over one million young zanders were planted into the lake; as a result, blue algae blooms decreased significantly. The decades of work for the conservation and restoration of Lake Vesijärvi have brought important environmental expertise into the city.



The condition of Lake Vesijärvi starts to improve

In the early 1990s, the results of the Vesijärvi I project started to show: the water quality improved and the life below the surface flourished. As the condition of Lake Vesijärvi improved, both fishermen and the people of the city returned to enjoy the lake near the city centre.



The Department of Environmental Ecology is established

The Department of Environmental Ecology of the University of Helsinki was established in Lahti. The Vesijärvi I project and the resulting research information in particular created a foundation for the teaching and research. The department has produced a lot of information on topics such as storm water, algae, green roofs, cleaning the soil and circular economy.

Ympäristöviikon kirpputori


The first annual Environment Week is held

Environmental education and the inclusion of citizens are an important part of the goals of the green city. The regional environment week has been arranged since 1997, and it encourages the companies and residents of the city to take green actions together.



An extensive waste management system is introduced

The new waste management system based on source separation was introduced. The separation of biowaste, energy waste, cardboard, paper and mixed waste started on properties with at least 10 apartments. The separate collection of energy waste and its use in energy production increased the waste recovery rate and decreased the amount of waste going to the landfill. In 1998, the recovery rate of waste was 25%.

Viking Maltin Polttimo


The Grain Cluster is founded

The Grain Cluster is a cooperation network of farmers and industrial companies in the Päijät-Häme area that develops circular economy and business in the field. Thanks to the development work by the cluster, the side streams created during the manufacturing processes of grain products are recovered better than ever and the amount of landfill waste has decreased.

Vesijärvi kaupungista päin


The Lake Vesijärvi Foundation is founded

The Lake Vesijärvi Foundation was founded to promote the water restoration work, monitoring and research that started in the 1970s. The Foundation has ensured a stable financing base for the water management in the Lahti region, because it combines public and private funding in a unique way.

Sinfonia Lahti


The first carbon-neutral symphony orchestra in the world

The Lahti Symphony Orchestra joined the climate effort with the goal of reducing the emissions due to its own activities and the mobility of the audience. The development project implemented together with the LUT University won the international Classical:NEXT innovation award in 2018.



The roadmap for circular economy is published

The first regional roadmap for circular economy in Finland sets goals and defines measures for promoting the regional circular economy of Päijät-Häme. The themes of the roadmap include bioeconomy, material circulation and new services, among other things.

Jätteiden keräys


97% of municipal waste is utilised

As a pioneer of circular economy, Lahti does not only reduce the amount of waste, it also uses the waste that is generated as efficiently as possible. One third of the waste generated in the area is recycled as raw material for new products, and the other two thirds are used to produce energy. But the goals are even higher than that: Lahti aims to be a fully waste-free city with a fully circular economy by 2050.

viimeinen kivihiilikasa


Goodbye to coal

Lahti stopped using coal in the spring of 2019, when the new bioenergy plant Kymijärvi III replaced the coal-fired Kymijärvi I power plant. The city is now heated with recycled fuel and local, certified wood. Significant energy transformation reduced Lahti Energia’s carbon dioxide emissions by 600,000 tonnes per year, which corresponds to the annual emissions of about 60,000 Finns.

Cycling in Lahti


A personal carbon trading scheme is tested

A model for personal carbon trading on mobility and an application for the citizens that enabled real-time tracking and visualization of one’s mobility carbon footprint was developed and tested in Lahti for the first time in the world.

Orkesteri Alatorilla


The European Green Capital year

Lahti has received the honour of becoming the European Green Capital as the first city in Finland. Large-scale cooperation projects will be launched and a number of international and local environmental events will be hosted. During the year, the best European environmental solutions are highlighted and the citizens, companies and communities are encouraged to take bold environmental action together.

Kerrostaloja ja puistomaisemaa


One of the Europe’s 100 forerunner cities

Lahti has been selected as one of Europe’s 100 forerunner cities. Lahti is involved in the EU Comission’s 100 Climate-neutral and Smart Cities Mission. Access to this EU mission directly supports the achievement of the city’s 2025 carbon-neutrality goal.

Juoksijat metsässä


Natural Step to Health program

Lahti sets out to connect nature and public health – kicks off a ten-year Regional Health and Environment Programme to integrate the health and environmental goals of the Päijät-Häme region.


A pioneer of the circular economy

The biogas plant built in cooperation between Lahti Energia and Hartwall will be opened. The facility, which operates purely on a local circular economy, produces energy from the mash produced as a byproduct of brewing beer. The mash is transported to the plant’s reactors via a pipe directly from Hartwall’s beer boilers. The material left over from the production is returned to the fields of the local Yli-Mäkelä farm to nourish the next barley crop, which will eventually end up in the beer boiler. Thanks to the merits of the biogas plant, Hartwall’s production in Lahti is carbon neutral. Lahti’s goal is to be a zero-waste circular economy city by 2050.

Nature-positive city

Lahti is beginning to calculate its ecological footprint. The ecological footprint indicates the extent of harm that a product, company, municipality, or consumer causes to biodiversity. The ecological footprint can also be positive, meaning the overall impact strengthens nature. Lahti aims towards a positive nature impact, striving for nature positivity.

Lahden keskusta ilmasta


Carbon-neutral Lahti

When Lahti leads, the rest of the world will follow. Lahti has set ambitious climate goals and intends to become a carbon-neutral by 2025 – ten years before the target set by the Finnish Government Programme and 25 years before the EU. As the first large carbon-neutral city in Finland, Lahti shows the way both for the other Finnish cities as well as internationally.