Fig. 3. Summary of the trade-offs between mean retention and cooling for different types of urban greening.

(A) Trade-offs between retention and cooling potential for different substrate thicknesses (h) and irrigation (Ir) applications. Points are means +/− standard error of the mean (SEM), shadings represent the binned and normalized frequency values for the intensive unirrigated substrate. (B) Histogram of global cities binned by PET/P alongside the fraction of retention or cooling potential offered by intensive substrate (h = 150 mm) and extensive substrate (h = 50 mm) as a fraction of the deep substrate (h = 1000 mm). The ratio of retention and cooling potential metrics is identical as both are equivalent to the ratio of AET between the respective substrate types. Values plotted as means +/- SEM.