Effects of climate change on river and groundwater nutrient inputs to the coastal ocean

Rivers and groundwater are major sources of nutrients to the global coastal ocean. Climate change is expected to impact nutrient fluxes from river basins and coastal aquifers through alterations to both hydrological and nutrient cycling processes. In this Review, we identify and summarize how climate change impacts, such as changes in precipitation, increased cryosphere melt, and sea level rise, will affect water discharge and nutrient concentrations in rivers and coastal groundwater, which ultimately control nutrient inputs to the coastal ocean. We also document key limitations in the current understanding of climate-related changes to nutrient fluxes, especially in coastal groundwater basins. The impacts of climate change will interact with local human impacts, highlighting the need for studies spanning local to global scales to better understand and improve predictions of future nutrient fluxes from these hydrological pathways. Nutrient fluxes from rivers and groundwater flowing into the ocean are impacted by climate change impacts such as precipitation changes, cryosphere melt, and sea level rise.