African environments are being altered at an explosive pace. A key priority in the coming decades will be increasing agricultural production and efficiency to improve food security and alleviate poverty for Africa’s rapidly growing population while harnessing the unprecedented scale of foreign investments focusing on land and natural-resource exploitation. The success or failure of these efforts will be influenced heavily by Africa’s development corridors, which will strongly affect future patterns of mining, land occupation, agriculture, and associated development pressures. Our analysis suggests that, as currently planned, a number of the development corridors would yield only limited agricultural benefits while severely degrading African ecosystems and wildlife. Concerted efforts are needed to reduce and mitigate these impacts.