One of the key scientific motivations for GEDI is to provide a quantitative, globally consistent, and transparent assessment of the spatial distribution of carbon stocks in the world’s forests at spatial resolutions relevant to monitoring, reporting, and verification of carbon stocks and flows.
GEDI data provide globally representative measurements of vertical structure in the world’s temperate and tropical forests. These measurements are used to quantify aboveground biomass density (AGBD) at the scale of individual GEDI footprints, each of which is approximately a 25 m diameter circle containing information on the vertical profile of the vegetation. Statistical models relate vertical height profiles to AGBD at locations where AGBD has been estimated from field inventories. These models are applied to the billions of GEDI profiles acquired during the 2-year mission life to predict AGBD, and its associated uncertainty, at the location of every profile measurement. These model predictions are publicly released as the GEDI Level 4A footprint aboveground biomass data product. Globally consistent measurements and algorithms help to overcome the uncertainties imposed by incomplete sampling and the use of different data sources and methods in different parts of the world. GEDI produces estimates of biomass at the level of individual footprints as well as 1 km gridded estimates, along with their associated uncertainties.
Estimates of land use change impacts on AGBD are produced by fusion with Landsat and other optical satellite imagery. Vegetation clearing disturbances mapped with Landsat are compared with co-located AGBD estimates produced by GEDI to quantify potential carbon emissions. A complementary approach is used to estimate carbon sequestration by vegetation regrowing after disturbance.
