All the mapping is at country level. Most subnational boundaries are removed for clarity. The mapping terms country, nation, or national do not imply any judgment on the legal status of any territory, or any endorsement or acceptance of disputed boundaries, on the part of CIESIN, the Trustees of Columbia University, or the data providers. The views expressed in the paper are those of the authors and not necessarily those of CIESIN, the Earth Institute, Columbia University, or NASA.