Wealth and wildlife in cities: How economic and demographic drivers influence global urban environmental injustice

Abstract Urban biodiversity is known to enhance the quality of life of urban dwellers, but its benefits are not equitably shared by the urban population. The positive correlation between urban biodiversity and socio‐economic status within cities (i.e. the Luxury Effect) can thus be considered a measure of environmental injustice. While common, this relationship is not universal, indicating a need to understand its drivers in an attempt to develop more equitable cities. This includes examining how economic and demographic contexts at larger spatial scales are associated with the Luxury Effect. We conducted a meta‐analysis to understand the extent to which wealth, income inequality, human population size and population density at city and national scales were associated with the strength of the Luxury Effect (the degree of correlation between urban biodiversity and socio‐economic status). Importantly, we considered non‐linear effects of these drivers, which are rarely considered in Luxury Effect studies. There was support for the Luxury Effect, with a positive relationship between biodiversity and socio‐economic status within cities. This relationship was generally stronger in poorer cities and countries. There was no support for an association with income inequality and the strength of the Luxury Effect at either city or national scales. We found support for an association between economic development and the strength of the Luxury Effect. Non‐linear effects were generally more supported than linear effects in that the Luxury Effect was strongest in countries with below average wealth, but was lowest in the poorest and wealthiest countries, and in cities with intermediate human population size. However, to adequately test the generality of these relationships, further research is needed in under‐represented countries, which, according to our findings, are those where levels of environmental injustice are likely greatest. Implications . The results suggest that poorer societies do not have the economic resources to confront the environmental injustice represented by the Luxury Effect. Identifying the drivers of the Luxury Effect, while also accounting for broader social challenges such as green gentrification, is fundamental to addressing environmental injustice and may help to prioritise strategies to reduce disparities in terms of gaining biodiversity benefits in cities globally. Read the free Plain Language Summary for this article on the Journal blog.