Using green infrastructure to improve urban air quality (GI4AQ)

TLDR

Air pollution poses severe health risks, and while green infrastructure is often promoted as a win‑win solution, its effectiveness varies by context, sometimes improving and sometimes worsening urban air quality. The authors introduce the GI4AQ framework and six policy interventions that guarantee green infrastructure will improve air quality, defining GI4AQ as green infrastructure with unambiguous benefits. Their conceptual framework explains the mechanisms by which green infrastructure can enhance air quality and specifies the six interventions that ensure its positive impact.

Abstract

As evidence for the devastating impacts of air pollution on human health continues to increase, improving urban air quality has become one of the most pressing tasks facing policy makers world-wide. Increasingly, and very often on the basis of conflicting and/or weak evidence, the introduction of green infrastructure (GI) is seen as a win–win solution to urban air pollution, reducing ground-level concentrations without imposing restrictions on traffic and other polluting activities. The impact of GI on air quality is highly context dependent, with models suggesting that GI can improve urban air quality in some situations, but be ineffective or even detrimental in others. Here we set out a novel conceptual framework explaining how and where GI can improve air quality, and offer six specific policy interventions, underpinned by research, that will always allow GI to improve air quality. We call GI with unambiguous benefits for air quality GI4AQ. However, GI4AQ will always be a third-order option for mitigating air pollution, after reducing emissions and extending the distance between sources and receptors.