Chapter

Methods in Ecosystem Science

pp 44-57

Global Terrestrial Gross and Net Primary Productivity from the Earth Observing System

  • Steven W. Running
  • , Peter E. Thornton
  • , Ramakrishna Nemani
  • , Joseph M. Glassy

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Probably the single most fundamental measure of “global change” of highest practical interest to humankind is the change in terrestrial biological productivity. Biological productivity is the source of all the food, fiber, and fuel by which humans survive, and so defines most fundamentally the habitability of Earth. The spatial variability of net primary productivity (NPP) over the globe is enormous, from about 1000 g Cm-2 for evergreen tropical rain forests to less than 30 g Cm-2 for deserts (Scurlock et al. 1999). With increased atmospheric carbon dioxide (CO2) and global climate change, NPP over large areas may be changing (Myneni et al. 1997a, VEMAP 1995, Melillo et al. 1993). Understanding regional variability in carbon cycle processes requires a more spatially detailed analysis of global land surface processes. Since December 1999, the U.S. National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) produces a regular global estimate of (gross primary productivity, GPP) and annual NPP of the entire terrestrial earth surface at 1-km spatial resolution, 150 million cells, each having GPP and NPP computed individually.