a, Changes (‘climate change’ minus ‘control’ period) in the number of occurrences of extreme pIOD events versus changes in the number of El Niño events defined as when the amplitude of the detrended Niño3 (5° S–5° N, 150° W–90° W) SST index is greater than 0.5 s.d. b, Changes in the number of extreme pIOD events versus changes in the number of El Niño events defined as when the Niño3 total rainfall is greater than 5 mm day−1 as in ref. 38. c, The same as b, except an extreme El Niño is determined from a detrended Niño3 (5° S–5° N, 150° W–90° W) SST index when its amplitude is greater than 1.5 s.d. d, Correlation between a detrended Niño3 index and a detrended DMI index1 for the ‘climate change’ (y axis) and the ‘control’ periods (x axis). e, Changes in the number of occurrences of extreme pIOD events versus changes in the number of Modoki El Niño events defined as when the amplitude of a detrended index39 (see Methods) is greater than 0.5 s.d. f, Correlation between a detrended El Niño index and a detrended DMI index for the ‘climate change’ (y axis) and the ‘control’ periods (x axis). The inter-model correlation and its statistical significance or otherwise are indicated in the bottom right corner of each panel, with a P-value less than 0.05, indicating significance above the 95% confidence level, a condition not met in a, b, c and e. Models with a stronger relationship between ENSO and the Indian Ocean dipole in the ‘control’ period tend to have a stronger such relationship in the ‘climate change’ period, and the tendency is statistically significant, although the relationship weakens slightly in the ‘climate change’ period. The same is true for the Modoki relationship between ENSO and the Indian Ocean dipole. Source data