Urban greenery is needed to protect cities from extreme heat

The article highlights their research in Vlaardingen, near Rotterdam, where the team stress-tested the municipality’s urban greening plans against thousands of possible future scenarios, including extreme heat, population growth and budget constraints. Research assistant Lukas van der Wolf of TU Delft also contributed to the study.

Making more green spaces

The findings show that simply planting more trees is not enough. In densely built-up parts of Vlaardingen, temperatures during heatwaves could be as much as four degrees higher than in surrounding areas. The effectiveness of urban greenery also depends heavily on long-term maintenance: newly planted trees can die, and without sufficient investment in their upkeep and replacement, the cooling benefits can quickly diminish.

In the AD article, Sylvia Bergh stresses that urban greening needs to become a structural part of municipal policy and budgets rather than something funded only when money happens to be available. The researchers argue that green infrastructure should be planned and financed in much the same way as roads and housing. A municipal greening plan, in other words, needs the same level of long-term attention and detail as a housing development plan.

The research also illustrates the difficult choices municipalities face. As Bergh explains in the newspaper, cities have multiple competing priorities. New housing also requires parking and other facilities, while creating and maintaining sufficient green space, requires land and sustained investment. Preparing cities for extreme heat therefore involves balancing these competing demands while ensuring that climate resilience is not treated as an afterthought.

The work forms part of the research project 'Stress-testing municipal urban greening plans for climate justice', carried out by Bhattacharyya, Bergh and Van der Wolf. The project examines whether current urban greening strategies will remain effective in a warmer climate towards 2050 and concludes that green space requires structural funding and long-term planning.