algorithm, utilizing more than 1,000,000 national and sub-national geographic units, is used to assign population values to grid cells. The population count grids are divided by the land area grid to produce population densities. This dataset is produced by the Columbia University Center for International Earth Science Information Network (CIESIN) in collaboration with the International Food Policy Research Institute (IFPRI), The World Bank, and Centro Internacional de Agricultura Tropical (CIAT). Citation: Socioeconomic Data and Applications Center (SEDAC), Columbia University (2011). For complete metadata see: http://sedac.ciesin.columbia.edu/downloads/metadata/grump-v1-population-density.html 2015 Population Density: Population Density: Gridded Population of the World, Version 3 (GPWv3) Future Estimates consists of estimates of human population for the year 2015 by 2.5 arc-minute grid cells and associated datasets dated circa 2000. A proportional allocation gridding algorithm, utilizing more than 300,000 national and sub-national administrative units, is used to assign population values to grid cells. The population counts that the grids are derived from are extrapolated based on a combination of subnational growth rates from census dates and national growth rates from United Nations statistics. All of the grids have been adjusted to match United Nations national level population estimates. The population count grids contain estimates of the number of persons per grid cell. Citation: Socioeconomic Data and Applications Center (SEDAC), Columbia University (2005). For complete metadata see: http://sedac.ciesin.columbia.edu/downloads/metadata/gpw-v3-population-density-future- estimates.html AVHRR 8KM Classification: 8KM Classification: The University of Maryland Department of Geography generated this global land cover classification collection in 1998. Imagery from the AVHRR satellites acquired between 1981 and 1994 were analyzed to distinguish fourteen land cover classes. Citation: Hansen, M., R. DeFries, J.R.G. Townshend, and R. Sohlberg (1998), UMD Global Land Cover Classification, 8 Kilometer, 1.0, Department of Geography, University of Maryland, College Park, Maryland, 1981-1994. For complete metadata see: http://www.glcf.umd.edu/data/landcover/description.shtml. AVHRR 1KM Classification: 1KM Classification: The University of Maryland Department of Geography generated this global land cover classification collection in 1998. Imagery from the AVHRR satellites acquired between 1981 and 1994 were analyzed to distinguish fourteen land cover classes. Citation: Hansen, M., R. DeFries, J.R.G. Townshend, and R. Sohlberg (1998), UMD Global Land Cover Classification, 1 Kilometer, 1.0, Department of Geography, University of Maryland, College Park, Maryland, 1981-1994. For complete metadata see: http://www.glcf.umd.edu/data/landcover/description.shtml Modis Classification: Classification: The MODIS Land Cover Type product (2003) is derived from observations spanning a year’s input of Terra and Aqua data. The land cover scheme identifies 17 land cover classes defined by the International Geosphere Biosphere Programme (IGBP), which includes 11 natural vegetation classes, 3 developed and mosiacked land classes, and three