It is still a challenge to simulate the so–called Green Sahara (GS), which was a wet and vegetative Sahara region in the mid–Holocene, using current climate models. Our analysis shows that Holocene greening is simulated better if the amount of soil nitrogen and soil texture is properly modified for the humid and vegetative GS period. Future climate simulation needs to consider consequent changes in soil nitrogen and texture with changes in vegetation cover for proper climate simulations.