Contrasting inequality in human exposure to greenspace between cities of Global North and Global South

Abstract

The United Nations specified the need for "providing universal access to greenspace for urban residents" in the 11th Sustainable Development Goal. Yet, how far we are from this goal remains unclear. Here, we develop a methodology incorporating fine-resolution population and greenspace mappings and use the results for 2020 to elucidate global differences in human exposure to greenspace. We identify a contrasting difference of greenspace exposure between Global South and North cities. Global South cities experience only one third of the greenspace exposure level of Global North cities. Greenspace exposure inequality (Gini: 0.47) in Global South cities is nearly twice that of Global North cities (Gini: 0.27). We quantify that 22% of the spatial disparity is associated with greenspace provision, and 53% is associated with joint effects of greenspace provision and spatial configuration. These findings highlight the need for prioritizing greening policies to mitigate environmental disparity and achieve sustainable development goals.

Fig. 1. Multiscale heterogeneities of human exposure to greenspace across the globe.

a–c Country-level, state-level, and county-level assessments of human exposure to greenspace using 500 m buffer zones, respectively, with darker green colors showing higher levels of greenspace exposure. Sensitivity of different buffer distances from 100 to 1500 m to the d country-level, e state-level, and f county-level assessments of human exposure to greenspace. The list of countries, states, and counties are ordered by greenspace exposure level estimated using the 500-m buffer zone.

Fig. 2. Greenspace exposure levels and the associated greenspace exposure inequalities measured by the Gini index for 1028 cities globally.

Larger bubble sizes represent higher levels of greenspace exposure, and warmer colors represent higher levels of greenspace exposure inequality. Administrative boundaries with light blue (pink) shading represent Global North (South) countries.

Fig. 3. Seasonal change of greenspace exposure inequality for 1028 cities globally.

a Histogram of seasonal greenspace exposure variation of each city, measured by the coefficient of spatiotemporal variation – std (σ/u). b Difference between the Gini index of greenspace exposure in summer (x-axis) and winter (y-axis). The bubble size represents the magnitude of the spatial and seasonal greenspace exposure variation of each city, measured by std (σ/u). Larger bubble sizes denote higher seasonal variation. c Attribution of the Gini index difference of greenspace exposure between summer and winter to the difference of σ/u between summer and winter with a significant positive correlation (R² = 0.59, p-value < 0.01). d Difference between the Gini index of greenspace exposure in summer and winter overlaid on Global South and Global North.