FIGURE 8.13 View of Earth’s gravity field acquired with the Gravity Recovery and Climate Experiment (GRACE). SOURCE: Courtesy of University of Texas Center for Space Research and NASA.

FIGURE 8.14 Topex/Poseidon and Jason missions ocean elevation monitoring. SOURCE: Courtesy of NASA/JPL.

FIGURE 8.15 Interferometric synthetic aperture radar mapping of earthquake displacement. SOURCE: Courtesy of Andrew Newman, Georgia Institute of Technology, http://geophysics.eas.gatech.edu.

tor the ocean temperature and currents, wind patterns under the cloud cover of hurricanes, changes of the ice cover at both poles, the dynamics of the ozone layer that protects life on Earth, the changes in the vegetation cover, among many other environmental elements. Within the next decade we will be able to measure the ocean salinity from space, map in three dimensions the emissions, circulation and absorption of carbon dioxide, the subtle tectonic motion of plates leading to assessment of high risk areas, monitor the changes in biomass and the full inventory of atmospheric gases, detect subtle changes in the surface water (with altimetric changes), and subsurface water (with gravity changes). Our ability to monitor from space almost all the “health symptoms” of our planet is putting us at the threshold of being able to provide the public and the policymakers with scientifically based knowledge of the present and future impact that we are having on our planet. As we better understand, improve and verify our global model, we will then be able to assess the impact of specific actions that are proposed to be a better custodian of our home planet.