From the objective stated above and in view of the given background, this research on urbanization and its impacts investigate a number science questions including:

Can the urban environment be characterized based on physical and measurable parameters such as infrastructures (houses, buildings, factories, etc.) together with high-resolution urban information content (e.g. light/optical data) rather than arbitrary political and administrative units? Can the rate of change in the urban environment be consistently and continuously delineated in the spatial and temporal continuum without gaps in a decadal timeframe and at the scale relevant to addressing key issues in environmental as well as social science? How does urban change, from mega urbanization like in Asia to stable urban areas, impact the environment through processes involving pollution (e.g., NO2), particulates (e.g., PM10 with size ~10 μm), green-house-gas (GHG) emission (CO2), urban heat island (UHI), urban dome, air quality and health exposure (e.g., smog, ozone), ground water contamination (e.g., nitrate), temperature change, light contamination, and urban-climate interactions? How does urban change affect the socioeconomic spectrum of spatial and structural transformations, including the role of the rural non-farm sector in towns and small cities, rural-urban migration decisions, the dynamics of land markets in peri-urban areas, the degree and nature of specialization in cities of different sizes and at different development stages, and the identification of urban agglomeration benefits and congestion diseconomies? Can mega urban change exacerbate water resource problems (e.g., drought and population dynamics in extreme urbanization) as well as natural and man-made disasters (e.g., extreme urbanization in regions prone to wild fire, flood, tsunami; infrastructure failures, etc.)?

In this research, observations (satellite, airborne, surface networks, census, demographic data, etc.) and model results (nesting climate, meteorological, gas, aerosol, and radiative parameters simultaneously from the global through urban scale) are anticipated to significantly address the above science questions. For example, we expect to quantify mega urban change and its impacts such as extreme increase in pollution.

The resulting product will ultimately present a unique resource which can be used not only as a global reference, but also a measure of urban change of the spatial distribution of human settlements in the decade of the 2000s for studies of urbanization, population distribution, land use, hazard vulnerability, and environmental and climate assessments. Because human settlements are important drivers of land use well beyond their immediate borders, achieving these objectives on a global scale would represent a major advance in our ability to systematically quantify the relationship among urban environment, human population, and other components of the Earth system.

Such a database will be significant as input and as verification to be used by urban and regional climate and air/groundwater pollution modelers interested in improved characterization of the land surface in urban areas, as well as by local and regional decision makers interested in improving regional-scale assessments of urban extent and associated infrastructure distribution. The database would also have utility in assessments of the consequences of land cover and land use change on ecosystem sustainability and the implications of climate and sea level changes and increased human activities on coastal developments.

The resulting data products would also have significant practical applications, especially in the area of hazard vulnerability assessment. In particular, the hazards community has long recognized the severe lack of data on the exposure of population and infrastructure to various types of hazards. We anticipate the research results to offer explanations on the pace and scale of urbanization and an understanding of what may lie ahead for urban environments in the coming decades.