How urban green infrastructure contributes to carbon neutrality

Ranja Hautamäki; Liisa Kulmala; Mari Ariluoma; Leena Järvi

doi:10.5334/bc.586

Figures & Tables

Carbon-smart urban green infrastructure (UGI) can be promoted across planning scales. Shown is the most effective means to enhance UGI and its climate benefits at different urban scales for a typical urban brownfield development.
*Source:* City of Helsinki, plans from Jätkäsaari.

Different types of urban green infrastructure (UGI) have different carbon sequestration and storage (CSS) capacities and emission rates and require different methods to enhance carbon sinks. Highlighted are the carbon fluxes and key CSS actions in an existing forest, a courtyard with soil-based greening and built greening on rooftop courtyards.
*Source:* Hautamäki (2025).

Table 1

Key action points for carbon-smart urban green infrastructure (UGI) across different scales and actors in planning, construction, and management.

SCALE AND ACTORS	PRESERVE UGI	CREATE A NEW UGI	LOW-EMISSION UGI
City- and district-scale urban planning and policies Urban planners	Set targets for carbon sinks of UGI in climate actions plans Integrate UGI into climate adaptation and biodiversity targets Preserve carbon sinks from urban development	Set quantitative greening and tree canopy cover targets Enhance the connectivity of UGI networks that combine carbon sinks, biodiversity and recreation	Integrate low-emission UGI practices into municipal climate action plans
Planning neighbourhoods and plots Urban planners, architects, private-sector developers	Use natural conditions, topography and vegetation as a starting point for planning Preserve existing vegetation, especially trees and soils Include the loss of carbon sinks in the climate impact assessment of urban development	Set quantitative targets, e.g. 30% tree canopy cover for neighbourhoods Increase multifunctional UGI that prevents flooding and heatwaves and supports carbon sequestration and storage (CSS), biodiversity, and wellbeing Minimise soil sealing and prioritise courtyards with contact with the soil Ensure sufficient space for greening	Apply life-cycle assessment (LCA) to compare alternative planning options and inform decisions on where and how to build
Planning and implementing parks, courtyards and street plantings Landscape architects, architects, constructors, property owners	Preserve existing vegetation, especially trees and soils Safeguard and maintain vegetation cover in the long term	Ensure good growing conditions, e.g. sufficient space for roots and the canopy, and the availability of water Promote multispecies and multilayered vegetation and native species	Reduce construction emissions, especially earthworks Use on-site soils or low-carbon and peat-free-growing media Choose recycled and low-carbon materials, e.g. paving
Maintaining UGI Landscape managers, constructors, communities, property owners	Protect trees and vegetation in construction sites Adopt maintenance practices that enhance both CSS and biodiversity Prioritise biodiversity-rich and low-maintenance meadows over lawns	Ensure good maintenance for newly planted vegetation, especially trees Optimise the intensity of maintenance for supporting both biodiversity and CSS	Prefer low-maintenance solutions Use low-emission electric machinery for on-demand maintenance Recycle leaf and mowing litter on-site

How urban green infrastructure contributes to carbon neutrality

Figures & Tables

Figure 1

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Table 1

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