Groundwater is the world’s largest, accessible store of freshwater. Groundwater is also the primary source of drinking water to nearly half of the world's population and, as the dominant source of water to irrigated land, is critical to global food security. Despite this dependence, our understanding of the impacts of climate change on groundwater resources remains limited. Strategies to adapt to more variable freshwater resources will, in many environments, increase dependence upon groundwater. At present, few impact models explicitly consider how climate variability and change affect groundwater recharge and the sustainable development of groundwater. Groundwater fluxes operating at a range of spatial and temporal scales require consideration. These fluxes include: (1) capillary flow from the water table to the root zone to sustain evapotranspiration during dry periods; (2) shallow groundwater discharges to local stream networks and other surface water bodies (e.g. lakes, wetlands); (3) deeper regional groundwater discharges to downstream river networks; and (4) submarine discharges in coastal areas. We invite contributions that quantify the scientific challenges of groundwater sustainability in respect of climate change impacts and encourage discussion of techniques for evaluating groundwater resources from satellite, surface and sub-surface data, and from land-surface modelling approaches. We also encourage aspects of the need to communicate coupled climate and hydrogeological information to assist adaptation responses to the pressures of human activities and climate change on groundwater resources.