This chapter discusses the effect of climate change on the dispersal of humans from their cradle in Africa to populate the entire world. The chapter starts with the models of origin including the multiregional model, the African origin model, and the African multiregional model. The chapter also discusses the potential routes that humans took to migrate from their African origin and the different dispersal views including the Single Late Dispersal hypothesis and the Multiple Early Onset Dispersals hypothesis. The chapter covers the climatic factors that caused humans to leave their initial habitat. This includes an overview of some scholarly studies which focus on the association between climate change and dispersal episodes in the cradle in East Africa, and how climate change opened corridors for humans to cross to other parts of the world. The chapter also includes a discussion on the dispersal through the Sahara and Arabian deserts to other parts of Eurasia and then concludes with the hypotheses on how the population of the Americas occurred. These include the Coastal Migration and the Ice-Free Corridor through the Bering Strait hypotheses.