Which biomes and marine biological zones have the highest NPP and, as a consequence, the greatest effect on atmospheric CO2 dynamics?

Knowing how NPP varies at a global scale is key to understanding how biotic factors affect the global carbon cycle and how future changes in biomes could affect climate change (see Concept 25.1).

Initial estimates of global NPP were based on compilations of plot-level measurements from different biomes, scaled up using estimates of the spatial distributions of those biomes. These estimates were subject to error associated with the uncertainty of the actual area covered by each biome type, as well as with the potential for overestimating NPP if undisturbed, old-growth study plots were selected to represent a biome. Remote sensing data now give us rapid direct measurements of NPP, providing an estimate of Earth's capacity to take up CO₂ and its response to climate variation and climate change.