Carbon Lane
- Helsinki, Finland


Urban cities are a major source of greenhouse gas emissions reduction


Carbon Lane project introduced urban demonstration sites for carbon sequestration

Urban areas are major source of CO2 emissions

With the recent increase in urbanisation in all parts of the world, there has been a lot of discussion about the relationship between climate change issues and cities. Since urban areas are a major source of greenhouse gas emissions, sustainable urban design is crucial for many countries and regions to achieve carbon neutrality. Helsinki, the capital city of Finland has published the Carbon Neutral Helsinki 2035 Action Plan, with the goal of making Helsinki carbon neutral by 2035. The strategy recognises the role of nature in capturing carbon dioxide and advocates increasing carbon sequestration. To this end, the city of Helsinki started a project which aimed to facilitate carbon sequestration and create an urban carbon cycle.

Carbon Lane Project in Helsinki

In 2019, the City of Helsinki launched the Carbon Lane project in partnership with two research institutes (Aalto University and University of Helsinki). The project combines establishing a carbon sequestration system with improving and maintaining the quality of urban green spaces. The Carbon Lane project has started construction of a new 100-hectare residential area in Jatkasaari in central Helsinki where demonstration sites were established for carbon sequestration in Hväntivompuis Park. The demonstration sites focused on trees and biochar to test the reliability and cost-effectiveness of urban carbon sequestration in public parks. Biochar is a material that utilises biomass, which is released into the atmosphere and becomes inorganic in a relatively short time, and is rich in carbon that is stable for hundreds to thousands of years. This allows carbon dioxide to be stored in the soil for a long time. Furthermore, biochar can improve soil and promote plant growth.

Co-designing Processes with Stakeholders

The key to the success of the Carbon Lane project in Helsinki was the widespread involvement of stakeholders. The project employed a co-designing process of idea and knowledge-sharing, and continuous dialogue through four workshops, involving various stakeholders (green building and gardening suppliers, researchers, policymakers, etc.). As a result, 32 different organisations participated in the process. The demonstration in Helsinki to build a network of stakeholders and co-design carbon sequestration solutions for urban green spaces made a significant contribution to the practice of carbon sequestration in cities.

More importantly, the project attempted to raise awareness of climate change mitigation by reaching out to city residents. For example, in order to raise awareness in the field, infographic posters, screens and other art forms were used to present carbon cycle and storage data in visually interesting and accessible charts, illustrations and text. In addition, by holding events and hands-on workshops in collaboration with civic groups, universities and companies, the project has succeeded in increasing the knowledge and awareness of citizens (e.g. how to use biochar in home gardens) and creating a sense of social unity related to the project. Furthermore, the use of web pages and social media has also played a role in raising this awareness among citizens. These efforts not only realise carbon sequestration in the city through the project but also inspire people to implement similar efforts in their own surroundings. In this way, the entire city can be shifted to a carbon-circulating system.

To summarise, the Carbon Lane project illustrates the design of a climate smart city, involving co-designing processes with city residents. Establishing carbon neutral systems is important to reduce CO2 emissions, but also offers opportunities to raise people’s awareness and facilitate actions for climate change mitigation. This is a good way to add value to the benefits of carbon sequestration as well as to increase the attractiveness of the city.