This chapter reviews the evidence on geography‘s causal impact on economic development. The economics research on the causal impact of the disease burden, climate and soil conditions, and topographical constraints has moved beyond cross-country correlations to exploit natural experiments, historical shocks, and fine-grained spatial variation. The evidence shows that geographical factors have clear causal effects on development outcomes, both directly and indirectly, with sub-Saharan Africa at a particular disadvantage. Moreover, climate change will only exacerbate this disadvantage.