Heterogeneity and scale of sustainable development in cities

Abstract

Rapid worldwide urbanization is at once the main cause and, potentially, the main solution to global sustainable development challenges. The growth of cities is typically associated with increases in socioeconomic productivity, but it also creates strong inequalities. Despite a growing body of evidence characterizing these heterogeneities in developed urban areas, not much is known systematically about their most extreme forms in developing cities and their consequences for sustainability. Here, we characterize the general patterns of income and access to services in a large number of developing cities, with an emphasis on an extensive, high-resolution analysis of the urban areas of Brazil and South Africa. We use detailed census data to construct sustainable development indices in hundreds of thousands of neighborhoods and show that their statistics are scale-dependent and point to the critical role of large cities in creating higher average incomes and greater access to services within their national context. We then quantify the general statistical trajectory toward universal basic service provision at different scales to show that it is characterized by varying levels of inequality, with initial increases in access being typically accompanied by growing disparities over characteristic spatial scales. These results demonstrate how extensions of these methods to other goals and data can be used over time and space to produce a simple but general quantitative assessment of progress toward internationally agreed sustainable development goals.neighborhoods | slums | urban services | spatial correlations | inequality T he current worldwide growth of cities presents at once an unprecedented historical opportunity for universal socioeconomic development and an immense challenge to global sustainability (1, 2). The mechanisms that generate improved living conditions and economic growth in cities-and that typically also increase overall energy and resource consumption-are still only partially understood (1-5) and remain hard to disentangle.Many recent studies have emphasized the environmental and geophysical adverse consequences of an increasing proportion of the planet's population living in cities and of the acceleration of this transformation in recent decades (6-8). The type and scope of these impacts vary but include air and water pollution, land-cover change, loss of natural habitats, strain on water resources, higher demand for energy, and rising greenhouse gas emissions (1,8,9).Conversely, the positive correlation between urbanization and many important dimensions of human development has also become increasingly clear. At the national level, the association between higher levels of urbanization and per capita economic productivity has been clear for some time (2). More recently, as city-scale data have become available, evidence has emerged for broader relationships between urbanization and better health, education, longer lifespans, and greater access to basic services, such as water or electricity, at lower...

Sustainability in an urbanizing planet

“…There were many individual case studies of the biological impacts of urbanization, or the health impacts of urbanization, but very little that was integrative across the different branches and that incorporated trade-offs or feedbacks. The articles in this Special Feature illustrate this point: each deals with one aspect of sustainability, such as biological (7), socioeconomic (8,9), biophysical (5), or technical (6). Each article acknowledges the need to create bridges among these fields and to examine urban and environmental systems as fully coupled or explicitly incorporating feedback loops.…”

“…8)? Several of the articles provide fine-grain data for a few cities (8,9), but assessments of the feedbacks and trade-offs across spatial scales are required as well.…”

“…Fourth, there is need for more theoretically grounded work building toward general explanations of our observations, potentially improving analytical options for projections of future outcomes (8,9). At least two theoretical pathways warrant attention.…”

Urban Metabolism of Three Cities in Jing-Jin-Ji Urban Agglomeration, China: Using the MuSIASEM Approach

“…In future research, land use data with a high resolution should be obtained to study the economic efficiency of different land use types, the proportion of different land use types and the relationships between human activity and land use in different sectors. Moreover, the inequalities within the urban population have recently drawn considerable attention in urban sustainable development research [60,61]. Further research on urban metabolism is necessary to reveal the inequalities among different income groups.…”

Early warning signals for landscape connectivity and resilient conservation solutions

“…Global anthropogenic activities and climate change are imperilling Earth's environment and undermining sustainable development for global conservation problems (Brelsford, Lobo, Hand, & Bettencourt, ). The escalating extent and concentration of urban populations coupled with changing landscape patterns have led to unprecedented changes in landscape connectivity (McRae, Dickson, Keitt, & Shah, ; Tilman et al, ).…”