Climate variability and change directly affect groundwater quantity and quality through changes in precipitation, evapotranspiration, recharge rates, and indirectly through changes in land use, irrigation and other human activities. Groundwater hydrology may respond across a variety of timescales, and vary across climatic and landscape gradients, for example with changing aridity and subsurface heterogeneity. Understanding human responses to climate variability is also crucial to the management of groundwater resources. This session seeks presentations that advance our understanding of the effects of natural climate variability and future climate change on (i) subsurface hydrology, such as groundwater recharge and aquifer vulnerability; (ii) fate and transport of carbon, nutrients, and subsurface contaminants; and (iii) human activities linked to groundwater, such as land use and pumping in response to droughts and/or floods. This session welcomes modeling, field, and laboratory studies investigating the impacts of climate variability and change on all spatial and temporal scales.