Figure 4. The ratios of future VGD changes predicted by a T_max-based GDD concept model to that predicted by a T_mean-based GDD concept model.

Both T_mean-based GDD approaches and T_max-based GDD models were applied to predict the VGD changes (▵VGD) between 1991–2010 and 2081–2100, using 24 climate models and different climate change scenarios (RCP2.6, RCP4.5 and RCP8.5). For each RCP, the T_max-based predictions and the T_mean-based predictions were averaged across all models and the distributions of their ratio (T_max-based predictions/T_mean-based predictions) are shown in (a), (b) and (c). The ratio <1 (blue bar) represents that the future VGD changes predicted by T_mean-based approaches are larger than those predicted by T_max-based approaches and vice versa (red bar). The percentage of ratios <1 and the percentage of ratios >1 are both provided in a,b and c.