From CCA:

Socioeconomic Data and Applications Centre, or SEDAC, is a branch of NASA that offers geospatial on human interactions with the environment. World datasets that are available for download include population and urban development and wilderness areas.
Other data focus on a specific area of the world. Most of the datasets
seem to be in some sort of grid or e00 format. Some of the sites also
offer maps of the data.http://sedac.ciesin.columbia.edu/  SEDAC Projects are designed to help users synthesize and apply earth
science and socioeconomic data and information in their research,
educational activities, analysis and decision making. These projects
include data products and applications that address various types of
interdisciplinary data integration.”