In summary, both tree cover and consequently biomass carbon on agricultural land tend to be higher in
humid regions. However, there is wide disparity between regions (Fig. S4): dry areas in both Central and South
America have more biomass carbon than the global average for this level of aridity. Similarly, South and North
America, West and Central Africa, Southeast Asia, and Australia/Pacific all rank above the global average for
semi-humid to arid regions, while Central Asia, Russia, Europe, and South, East and West Asia have lower than
expected biomass carbon. Thus, in many regions there is still potential for increasing biomass carbon on agricultural
land.