Extended Data Fig. 5: Schematic of Climate envelope model (CEM) and Habitat suitability model (HSM) set-up.

The orbital scale transient 2Ma simulation of CESM1.2 is conducted by using CO₂ and ice-sheet forcings from an intermediate complexity model simulation¹⁵ and orbital forcing from astronomical estimates¹⁶. The simulated surface temperatures and precipitation from 2Ma on a ~3.75-degree horizontal grid are then downscaled to a 1x1 degree horizontal grid by including lapse-rate corrected topographic features. Net Primary Production is calculated from empirical parameterizations of the downscaled temperature and precipitation fields (Extended Data Fig. 8d–f). Using an extended fossil and archaeological database (Supplementary Table 1) in combination with the downscaled annual mean temperatures, annual mean rainfall, minimum rainfall and net primary productivity, a statistical Mahalanobis distance-based climate envelope model (CEM) is derived. The model is then forced for every land grid point on a 1x1 degree grid with the temporal evolution of the downscaled climate variables to obtain the temporal evolution of the habitat suitability (HSM) for each of the 5 hominin groups and at every grid point. The impact of resolution on key features in simulated net primary production is further illustrated in Extended Data Fig. 8d–f.