There is the same amount of freshwater on earth as there always has been, but the population has exploded, leaving the world's water resources in crisis.
The water you drink today has likely been around in one form or another since dinosaurs roamed the Earth, hundreds of millions of years ago.
While the amount of freshwater on the planet has remained fairly constant over time—continually recycled through the atmosphere and back into our cups—the population has exploded. This means that every year competition for a clean, copious supply of water for drinking, cooking, bathing, and sustaining life intensifies.
Water scarcity is an abstract concept to many and a stark reality for others. It is the result of myriad environmental, political, economic, and social forces.
Due to geography, climate, engineering, regulation, and competition for resources, some regions seem relatively flush with freshwater, while others face drought and debilitating pollution.