Figure 3.

Δ water supply gap index. Map of the Δ water supply gap index, which measures the ability of the land surface to meet evaporative demand of the atmosphere. A narrowing water supply gap (cool colors) indicates sufficient water and widening water supply gap (warm colors) indicates that water is limited. The water supply gap is only defined over land and values that do not pass a significance test at 95% confidence have been omitted. The anomaly compares a case where northern mid-latitudes are afforested as in Fig. 1A with the control (TREE-CON).