Socioeconomic Data and Applications Center (SEDAC)

http://sedac.ciesin.columbia.edu/ offers a multitude of (mostly global) geospatial data sets for various topics such as agriculture, climate, conservation, governance, natural hazards, infrastructure, land use, population, sustainability as well as urban areas and water. The data can be immediately visualized in form of a map, accessed as a remote service, e.g., WMS, from GIS software, or downloaded. Also, a ready-to-use map is offered in form of an image or PDF file.