Amidst rising human-induced water demands, which have historically been met by expanding surface water reservoir storage, society’s reliance on groundwater usage has increased by 50% over the last 50 years. Effective long-term planning to meet future multi-sector water demands (e.g., by mid-century) requires better understanding of the relative roles that groundwater and surface water may play, not just in a particular region of interest, but also globally, as the world is teleconnected through trade. Here, we seek to understand how groundwater and surface water supply might evolve into the future globally under an array of uncertain human and earth system forces, such as socioeconomic and technological change and climate impacts on water availability. To do this, we use the Global Change Analysis Model (GCAM) – a coupled model of the human-Earth system that represents the dynamic interactions between socioeconomic, energy, land, water, and climate systems at global scale within an internally consistent economic modeling framework. Using a large ensemble of 900 GCAM simulations that spans a diversity of uncertain human and earth system dimensions of global change, we use scenario discovery techniques to identify scenarios that lead to changes in non-renewable groundwater extraction, as well as scenarios that lead to peak usage of non-renewable groundwater globally and regionally. Among other influencing factors, we find that the cost and availability of surface water storage could especially play a strong role in how groundwater evolves – driving when and where it peaks – which has major implications for agro-economic trade and development. With expanding surface water storage, society’s dependence on groundwater would diminish and result in reduced and delayed peaks of groundwater extractions over the 21st century. Groundwater challenges in western United States, India, China, Pakistan, and the Middle East, such as exhaustion of economically accessible groundwater or approaching peaks in groundwater withdrawals, could have strong implications for the future of water storage and use on other continents, and imply substantial investments and management shifts in both groundwater and surface water sectors in other parts of the world.