To beat the heat, cities need to scale up green infrastructure

The research, carried out in Stockholm Royal Seaport, utilized a network of wireless sensor stations to monitor real-time temperature variations across different types of NbS: forest parks, green courtyards, rain gardens, green roofs, and lawns.

Scaling up green infrastructure is necessary

The results, published in ScienceDirect, indicate that the local cooling impact of NbS was less significant than expected, suggesting that broader regional weather patterns dominate microclimatic conditions in Stockholm Royal Seaport.

“Temperature differences between NbS types were relatively small, with a maximum variation of 2°C during summer, which diminished in cooler months. Forest parks consistently provided the most cooling, while green roofs were the warmest among the studied NbS,” says Timon McPhearson, Centre associate, who carried out the study together with Erik Andersson and former Center reseacher Arthur Branny.

These findings highlight that while NbS contribute to urban climate adaptation, their cooling benefits cannot be assumed without systematic evaluation. The study stresses that scaling up green infrastructure at a district-wide level is necessary for meaningful temperature regulation.

Implications for Urban Planning and Climate Adaptation

The study provides guidance and a number of useful takeaways for urban practitioners and decision makers working with NbS.

1. Scale Matters
   Small, isolated NbS have limited impact on local cooling, NbS need to be integrated at larger district scales to effectively reduce urban heat. Cities should prioritize interconnected green spaces over scattered small interventions for better urban heat mitigation.
2. Beyond Temperature Regulation
   NbS provide other critical ecosystem services, such as stormwater management, biodiversity support, and improved human well-being. Policymakers and planners should consider these co-benefits, not just temperature reduction.
3. Real-Time Monitoring for Informed Decision-Making
   The study showcases the value of continuous, real-time sensor data in evaluating NbS performance. Cities should invest in monitoring systems to track the long-term effectiveness of green infrastructure. The study suggests combining sensor data, remote sensing, and urban climate modeling to better assess NbS performance.
4. Urban Morphology and Regional Context Are Critical
   The impact of NbS is influenced by urban form, regional climate, and surrounding land uses. Cooling effects are stronger when NbS are strategically placed in relation to wind corridors, shaded areas, and water bodies.

“For urban planners, architects, and policymakers, this study reinforces the importance of scaling up NbS and using data-driven approaches for climate adaptation. While NbS are valuable, their effectiveness in cooling cities depends on integration, scale, and strategic urban design,” concludes Timon McPhearson.