Greening cities that are becoming denser is a major challenge. City-dwellers' health benefits from both well-designed green spaces and urban density, so we must manage the tensions between them.
Urban greening programs need to consider the harmful impacts of artificial lighting on ecosystems. Fortunately, we can do a lot to create more biosensitive lighting.
Recently published research has found that the concentration of poorer people in hotter places is a real problem for cities' capacity to cope with climate change.
The rise of urban greening is an opportunity to recast the relationship between people and environment. Humans and non-human species are ecologically intertwined as inhabitants of cities.
Not only do healthy, well-maintained trees provide shade and benefit the ecosystem, they can have a meaningful social impact: people in newly greened neighbourhoods start to look out for each other.
Green infrastructure can be delivered relatively easily using existing planning processes. The main obstacle could be psychological: planners are wary of disruption to embedded practices.
Achieving green cities will require more than just canopy cover targets and central city strategies. It will need new approaches to urban planning and development.
It seems like a 'no brainer' to use urban greening to help cities adapt to increasing heat, but the uptake of green infrastructure, such as trees and vegetated roofs, surfaces and walls, is slow. Why?