A global meta-analysis of effects of green infrastructure on COVID-19 infection and mortality rates

Evidence of the benefits of greenspaces or greenness to human wellbeing in the context of COVID-19 is fragmented and sometimes contradictory. This calls for a meta-analysis of existing studies to clarify the matter. Here, we identified 621 studies across the world, which were then filtered down to 13 relevant studies covering Africa, Asia, Europe, and USA. These studies were meta-analysed, with the impacts of greenspaces on COVID-19 infection rate quantified using regression estimates whereas impacts on mortality was measured using mortality rate ratios. We found evidence of significant negative correlations between greenness and both COVID-19 infection and mortality rates. We further found that the impacts on COVID-19 infection and mortality are moderated by year of publication, greenness metrics, sample size, health and political covariates. This clarification has far-reaching implications on policy development towards the establishment and management of green infrastructure for the benefits of human wellbeing.