Local mountain communities, as well as communities downstream, depend on mountain ecosystems and their services for livelihood. Today, mountain communities are experiencing rapid change through globalization, modernization, political, and demographic changes. While some of these changes offer most needed development options to mountain people, others result in significant pressure on the sensitive social-ecological systems in mountains. Stress that is further exacerbated by impacts of climate change and is threatening the sustained provision of key ecosystem services that support communities in mountains and lowlands and the capacity of mountain social-ecological systems to cope with disturbances and unexpected shocks. Understanding these complex processes under uncertain global change requires a systematic and integrative approach to analyze these interactions in terms of their trends and impacts on the resilience of social-ecological systems in mountains and their ability to transform into thriving communities and a sustainably managed environment. Ideally, such an approach spans across space, time, and includes diverse types of knowing and observing these changes.