This animated graphic outlines the 15 NASA Earth science missions recommended by the National Research Council in its decadal survey report, published in 2007. These future missions will form the basis of a systematic space-based study of the Earth. For more information about the survey and the missions, see this NASA Science article, this decadal survey Web site, and the NRC's report.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 18.104.22.168.0