Most of Earth's freshwater is locked in Antarctic ice, leaving only a sliver readily accessible

More than two-thirds of Earth's freshwater is frozen in ice caps and glaciers, with Antarctica alone holding about 70% of all fresh water (roughly 28–30 million cubic km). While the global stock is vast, the portion that is easily usable is tiny—about 1% of total freshwater—leaving the majority of water either locked in ice or buried too deep for practical extraction. Groundwater accounts for roughly 30% of freshwater, but much of it is not readily pumpable; the upshot is that water security depends on access and distribution, not total supply.