Climate and geography shape where and why conflicts occur. As part of an effort to characterize the future of warfare in 2030, this report assesses the implications of six key climate and geographical trends: the steady rise of global temperatures, the opening of the Arctic, sea level rise, more-frequent and more-extreme weather events, growing water scarcity, and the development of megacities. The ramifications of each trend are analyzed for how they are likely to affect security in specific areas. Implications for the U.S. Air Force are also considered. While these trends on their own are unlikely to lead to state collapse or interstate conflict, they are nonetheless threat multipliers and are likely to exacerbate existing problems and fuel instability around the world. This suggests that the U.S. military, including the Air Force, will have to deal with continued demand for counterterrorism and stability operations and with increased demand for humanitarian assistance and disaster relief missions in the years to come. These trends could also shape where and how the Air Force trains and operates as bases are affected by extreme temperatures and flooding from sea level rise. Book jacket.