Figure 1

Persistent changes to TN90p (hot nights) and TX90p (hot days) have already occurred over large parts of the Earth and climate models underestimate these persistent changes. Top panels show time of emergence (TOE) of persistent changes to TN90p (a) and TX90p (b) derived from HadEX2 observations. Warm (cool) color marks regions where the emergence of persistent changes occurs in the direction consistent with warming (cooling). Gray color marks regions for which there is no emergence in HadEX2 observations by the year 2000. White regions have no data. See Fig. S7 for CMIP5 results corresponding to these panels. Bottom panels show the fraction of CMIP5 ‘Historical’ simulations that exhibit a delay of emergence of persistent changes to TN90p (c) and TX90p (d) or show emergence in a direction opposite to that observed (see Methods). It is noted that simulated emergence in the opposite direction to observed is restricted mainly to the ‘warming hole’ in southeast/central USA and to a few ensemble members (see Fig. S8). See Fig. S2 for TN10p (cold nights) and TX10p (cold days). The map is produced using R version 3.0.3 software (https://www.r-project.org/).