Fig. 4: African changes of the Holocene hydroclimate.

a Reconstructed slope of the Northern Hemisphere temperature gradient (LTG) (black, see ref. ⁵) between the low-latitudes and high-latitudes and the temperature contrast (purple, see ref. ¹⁸) calculated from zonal averages for the tropical region (30°S to 30°N) and the Northern Hemisphere extra-tropics (>30°N). b standardised inferred precipitation changes that are associated with shifts of the intertropical convergence zone (ITCZ) inferred from a speleothem δ¹⁸O record from Qunf cave (Oman)²⁷. The thin line is the original standardised proxy time series, while the thick line is the smoothed standardised proxy time series, using the same kernel method as for the calculation of the composite hydroclimate records (see ‘Methods' section). c Standardised precipitation changes associated with the African Monsoon (red) and the mean interhemispheric insolation contrast between 30°N and 30°S for June to August (JJA) (bold grey line). Changes in the insolation contrast are given relative to present-day. A positive insolation contrast indicates that the Northern Hemisphere received more insolation than the Southern Hemisphere relative to present-day. d Standardised mode of southern African precipitation changes (yellow) and the mean interhemispheric insolation contrast between 30°N and 30°S for (bold grey line) during austral summer (December to February, DJF). Changes in the insolation contrast are given relative to present-day. e Standardised precipitation changes in southwestern Africa. f Standardised precipitation changes in southeastern Africa. Arrows point in the direction of increasing insolation quantities or an increasing slope. Shading indicates the 1-sigma standard deviation.