Global change and groundwater

Groundwater (contained in sediments and rocks) constitutes the planet’s predominant reserve of fresh water, commonly with storage times from decades to centuries and millennia. Groundwater resources thus provide an excellent ‘buffer’ against the effects of climate variability on surface-water supplies, because of the generally large and widely- distributed storage reserves of aquifer systems. But questions arise as to how naturally resilient are groundwater reserves themselves to global change, and whether we are doing enough to help conserve and protect them.