As a result of rapid climate change and the associated changes in recharge and evapotranspiration patterns, groundwater resources will become gradually more stressed bringing about potential acceleration in groundwater depletion. Climate change may cause a decline of fresh groundwater through reduced recharge and/or increased pumping. This may disrupt the current water balance of the freshwater/ saline water boundary, resulting in salt water intrusion in not only coastal basins, but inland aquifers as well.
Coastal aquifers are more vulnerable to groundwater extraction because of high population densities and predicted sea-level rise. A low rate of natural groundwater recharge in combination with sea-level rise can introduce and accelerate movement of saltwater into freshwater aquifers. Seawater intrusion has affected groundwater quality in major coastal irrigation regions around the globe where pumping has destabilized the hydraulic equilibrium of the aquifers.