Among the future trends that will affect the U.S. Marine Corps and its ecosystems is climate change. This article examines past impacts of weather on military operations and the effects of climate change on current and future military activities and infrastructure. It makes a security-based assessment for the Marine Corps to develop greater expertise and capability to include climate and meteorological factors into its strategic- and tactical-level planning and operations. Finally, the article concludes with recommendations for the Marine Corps that can mitigate current and future drivers of fragility.