We explore and quantify the manifold impacts of urbanization on ecosystems and the services they provide.
In determining the effects of urbanization on the environment we draw data from weather stations, field interviews, satellite images, and governmental records. We develop new algorithms for processing this data, apply spatial statistical analysis to discover trends, and use coupled human–environment system models to predict future impacts.
The conversion of Earth’s land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It hastens the loss of highly productive farmland, affects energy demand, alters the climate, modifies hydrologic and biogeochemical cycles, fragments habitats, and reduces biodiversity (Seto et al., 2011) We see these effects on multiple levels. Future urbanization will, for example, pose direct threats to high-value ecosystems: the highest rates of land conversion over the next few decades will likely take place in biodiversity hotspots that were relatively undisturbed by urban development in 2000 (Seto et al., 2012). Within cities, the nature of urban growth is also an important determinant of urban dwellers’ vulnerability to environmental stress (Güneralp and Seto, 2008).
The environmental impacts of urban expansion reach far beyond urban areas themselves. In rapidly urbanizing areas, agriculture intensifies on remaining undeveloped land and is likely to expand to new areas, putting pressure on land resources (Jiang et al., 2013). Furthermore, urban areas change precipitation patterns at scales of hundreds of square kilometers (Kaufman et al., 2007) . Urban expansion will affect global climate as well. Direct loss in vegetation biomass from areas with high probability of urban expansion is predicted to contribute about 5% of total emissions from tropical deforestation and land-use change (Seto et al., 2012). The scope and scale of these impacts is yet to be fully researched. Although many studies have described how urbanization affects CO2 emissions and heat budgets, effects on the circulation of water, aerosols, and nitrogen in the climate system are only beginning to be understood (Seto & Shepherd, 2009).