Fig. 1: ISM precipitation responses to CDR.

a Timeseries of forced atmospheric CO₂ concentration (black), simulated global (solid), NH (dashed), and SH (dotted) averaged annual mean surface air temperature (red), and ISM precipitation (blue; June to October averages; lands in 70–87.5°E, 8.5–26°N) in CESM1 28 ensemble simulation averages. Vertical gray dashed lines separate the CO₂ ramp-up, ramp-down and stabilization periods. The shading highlights the 50-year periods: (i) characterized by the largest hysteresis (negative overshoot) in ISM precipitation during CO₂ ramp-down period (years 2231–2280) and (ii) corresponding equivalent global warming levels appeared during CO₂ ramp-up phase (years 2035–2084). b Spatial pattern of the RD-RU precipitation (shading) and 850 hPa horizontal wind (vectors) averaged from June to October in CESM1 28 ensemble simulation averages. c–g Same as (b), but for (c) June, (d) July, (e) August, (f) September and (g) October, including precipitation responses within ocean. b–g Black hatchings indicate regions with statistically significant precipitation differences at the 5% level based on a two-sided Student’s t-test; vectors are shown in black where the zonal or meridional winds exhibit significant differences at the 5% level based on a two-sided Student’s t-test, while colored gray when neither shows significant differences. b, c Blue boxes delineate Western Ghats (left box; since precipitation in that area is concentrated along the Western Ghats; lands within 70–76.875°E, 8.5–23.5°N), south-central-east India (right upper box; lands within 76.875–87.5°E, 13–26°N), and Tamil Nadu (right lower box; the southernmost state of India; lands within 76.875–80°E, 8.5–13°N) (only the lands within the boundaries are assigned to the individual regions).