Our Data

In December 1999, the National Aeronautics and Space Administration (NASA) launched the first Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite, followed by the Aqua, launched in May 2002. These instruments have been providing reasonably validated global productivity data since that time. However, these data remain underutilized for a number of reasons, foremost among which is a lack of understanding of the meaning of these data among potential consumers outside the carbon science field. Net Primary Productivity (NPP), an annual estimate of vegetation productivity, is presented as kg C/m2, Gross Primary Productivity (GPP) as kg C/m2 per eight-day period, both with a scaling factor of 0.0001. Though these data contain the essential information required to inform carbon markets on global terrestrial carbon sequestration activity, their use has not been adopted on any large scale for this purpose. To facilitate use of this wealth of ecological information, we developed a format to evaluate and compare various sites in terms of their carbon sequestration (productivity) value. We used NPP data and placed a dollar value on carbon as sequestered by vegetation.

To create the index, we used NPP values from sites where NPP is available. GPP data is available for free download at http://daac.ornl.gov/MODIS/modis.shtml. Selected field sites offer NPP data; these data are available for free, immediate download at http://daac.ornl.gov/cgi-bin/MODIS/GR_col5_1/mod_viz.html. National indices were generated for countries hosting five or more sites. More than 1,000 flux tower validated MODIS field sites were used to generate a global carbon index.

See our calculation methods here.