The potential of urban greenery as a climate solution is not being fully utilized – a new handbook offers means to address this

Parks, yards, street plantings and urban forests play a significant but still largely untapped role in mitigating climate change. In addition to sequestering carbon, they cool cities, manage stormwater, increase biodiversity and support human well-being.

In the multidisciplinary CO-CARBON project, researchers have investigated the climate benefits of urban greenery and developed solutions for its more effective utilization.

The handbook, published 20 May, brings together for the first time key research findings and recommendations on how to enhance carbon sequestration through urban greenery and how to design, build, and maintain green infrastructure in a low-emission manner.

“The aim is to integrate urban greenery more closely into climate and nature goals and their practical implementation”, says Ranja Hautamäki, Professor of Landscape Architecture at Aalto University. 

Carbon wisdom requires both broad strategies and small everyday actions

The key message of the handbook is that carbon wisdom is not just a matter of strategy. It is realized just as much in zoning and urban planning as it is in individual yards.

In addition to reducing emissions, cities’ carbon neutrality goals require strengthening carbon sinks. Investing in urban greenery is a key means to this end –and at the same time, an investment in a more pleasant, sustainable and healthier urban environment.

The Handbook for carbon-smart urban green addresses this need and presents ways to more effectively harness the potential of urban greenery as a cost-effective and multi-benefit climate solution. In addition to solutions, the handbook discusses methods for assessing carbon-smart practices and the practical application of this knowledge.

The handbook was developed as part of the CO-CARBON project, which involves the University of Helsinki, Aalto University, the Finnish Meteorological Institute, Häme University of Applied Sciences, and the University of Copenhagen, as well as a wide range of cities, companies, and other partners.

The Handbook for carbon-smart urban green

The “Lungs of the City” exhibition, illustrating the carbon cycle in green spaces, will be on display at Tiedekulma until 16 October, 2026.

Publications and tools produced by the CO-CARBON project to promote carbon wisdom:

• Policy recommendations for cities  
• Home yard carbon gardening
• Urban Tree Manifesto and canopy cover atlas

Further information:

Ranja Hautamäki
Professor, Landscape Architecture
ranja.hautamaki@aalto.fi
+358 50 523 2207